diff --git a/src/server/ble_2904.rs b/src/server/ble_2904.rs
deleted file mode 100644
index c13a23e..0000000
--- a/src/server/ble_2904.rs
+++ /dev/null
@@ -1,107 +0,0 @@
-use alloc::sync::Arc;
-use zerocopy::{IntoBytes, TryFromBytes};
-use zerocopy_derive::{Immutable, IntoBytes, KnownLayout, TryFromBytes};
-
-use crate::{utilities::mutex::Mutex, BLEDescriptor};
-
-#[derive(TryFromBytes, KnownLayout, IntoBytes, Immutable)]
-#[repr(u8)]
-pub enum BLE2904Format {
-  BOOLEAN = 1,
-  UINT2 = 2,
-  UINT4 = 3,
-  UINT8 = 4,
-  UINT12 = 5,
-  UINT16 = 6,
-  UINT24 = 7,
-  UINT32 = 8,
-  UINT48 = 9,
-  UINT64 = 10,
-  UINT128 = 11,
-  SINT8 = 12,
-  SINT12 = 13,
-  SINT16 = 14,
-  SINT24 = 15,
-  SINT32 = 16,
-  SINT48 = 17,
-  SINT64 = 18,
-  SINT128 = 19,
-  FLOAT32 = 20,
-  FLOAT64 = 21,
-  SFLOAT16 = 22,
-  SFLOAT32 = 23,
-  IEEE20601 = 24,
-  UTF8 = 25,
-  UTF16 = 26,
-  OPAQUE = 27,
-}
-
-#[derive(TryFromBytes, KnownLayout, IntoBytes, Immutable)]
-#[repr(packed)]
-struct Data {
-  format: BLE2904Format,
-  exponent: u8,
-  unit: u16,
-  namespace: u8,
-  description: u16,
-}
-
-pub struct BLE2904 {
-  descriptor: Arc<Mutex<BLEDescriptor>>,
-}
-
-impl BLE2904 {
-  pub(super) fn new(descriptor: Arc<Mutex<BLEDescriptor>>) -> Self {
-    descriptor.lock().set_value(
-      Data {
-        format: BLE2904Format::OPAQUE,
-        exponent: 0,
-        unit: 0,
-        namespace: 1,
-        description: 0,
-      }
-      .as_bytes(),
-    );
-
-    Self { descriptor }
-  }
-
-  pub fn format(&mut self, value: BLE2904Format) -> &mut Self {
-    Data::try_mut_from_bytes(self.descriptor.lock().value_mut().as_mut_slice())
-      .unwrap()
-      .format = value;
-
-    self
-  }
-
-  pub fn exponent(&mut self, value: u8) -> &mut Self {
-    Data::try_mut_from_bytes(self.descriptor.lock().value_mut().as_mut_slice())
-      .unwrap()
-      .exponent = value;
-
-    self
-  }
-
-  pub fn unit(&mut self, value: u16) -> &mut Self {
-    Data::try_mut_from_bytes(self.descriptor.lock().value_mut().as_mut_slice())
-      .unwrap()
-      .unit = value;
-
-    self
-  }
-
-  pub fn namespace(&mut self, value: u8) -> &mut Self {
-    Data::try_mut_from_bytes(self.descriptor.lock().value_mut().as_mut_slice())
-      .unwrap()
-      .namespace = value;
-
-    self
-  }
-  pub fn description(&mut self, value: u16) -> &mut Self {
-    Data::try_mut_from_bytes(self.descriptor.lock().value_mut().as_mut_slice())
-      .unwrap()
-      .description = value;
-
-    self
-  }
-}
diff --git a/src/server/ble_characteristic.rs b/src/server/ble_characteristic.rs
index f7f6c82..be2feef 100644
--- a/src/server/ble_characteristic.rs
+++ b/src/server/ble_characteristic.rs
@@ -2,18 +2,17 @@ use alloc::{boxed::Box, sync::Arc, vec::Vec};
 use bitflags::bitflags;
 use core::{cell::UnsafeCell, ffi::c_void};
 use esp_idf_svc::sys;
-
-#[cfg(cpfd)]
-use crate::cpfd::Cpfd;
+#[cfg(not(cpfd))]
+use zerocopy::IntoBytes;
 
 use crate::{
   ble,
+  cpfd::Cpfd,
   utilities::{
     ble_hs_mbuf_from_flat, ble_npl_hw_enter_critical, ble_npl_hw_exit_critical, mutex::Mutex,
     os_mbuf_append, voidp_to_ref, BleUuid,
   },
   AttValue, BLEConnDesc, BLEDescriptor, BLEDevice, BLEError, DescriptorProperties, OnWriteArgs,
-  BLE2904,
 };
 
 cfg_if::cfg_if! {
@@ -209,15 +208,6 @@ impl BLECharacteristic {
     descriptor
   }
 
-  pub fn create_2904_descriptor(&mut self) -> BLE2904 {
-    let descriptor = Arc::new(Mutex::new(BLEDescriptor::new(
-      BleUuid::Uuid16(0x2904),
-      DescriptorProperties::READ,
-    )));
-    self.descriptors.push(descriptor.clone());
-    BLE2904::new(descriptor)
-  }
-
   pub(crate) fn construct_svc_def_descriptors(&mut self) -> *mut sys::ble_gatt_dsc_def {
     if self.descriptors.is_empty() {
       return core::ptr::null_mut();
@@ -300,6 +290,17 @@ impl BLECharacteristic {
     self.cpfd[0].description = cpfd.description;
   }
 
+  #[cfg(not(cpfd))]
+  /// Set the Characteristic Presentation Format.
+  pub fn cpfd(&mut self, cpfd: Cpfd) {
+    let descriptor = Arc::new(Mutex::new(BLEDescriptor::new(
+      BleUuid::Uuid16(0x2904),
+      DescriptorProperties::READ,
+    )));
+    descriptor.lock().set_value(cpfd.as_bytes());
+    self.descriptors.push(descriptor);
+  }
+
   pub(super) extern "C" fn handle_gap_event(
     conn_handle: u16,
     _attr_handle: u16,
diff --git a/src/server/ble_hid_device.rs b/src/server/ble_hid_device.rs
index 6cdae30..7341a53 100644
--- a/src/server/ble_hid_device.rs
+++ b/src/server/ble_hid_device.rs
@@ -1,9 +1,9 @@
 use alloc::sync::Arc;
 
 use crate::{
+  cpfd::*,
   utilities::{mutex::Mutex, BleUuid},
-  BLE2904Format, BLECharacteristic, BLEServer, BLEService, DescriptorProperties, NimbleProperties,
-  BLE2904,
+  BLECharacteristic, BLEServer, BLEService, DescriptorProperties, NimbleProperties,
 };
 
 const BLE_SVC_DIS_CHR_UUID16_MANUFACTURER_NAME: BleUuid = BleUuid::from_uuid16(0x2A29);
@@ -24,7 +24,6 @@ pub struct BLEHIDDevice {
 
   battery_service: Arc<Mutex<BLEService>>,
   battery_level_characteristic: Arc<Mutex<BLECharacteristic>>,
-  battery_level_descriptor: BLE2904,
 }
 
 impl BLEHIDDevice {
@@ -56,11 +55,13 @@ impl BLEHIDDevice {
       BLE_SVC_BAS_CHR_UUID16_BATTERY_LEVEL,
       NimbleProperties::READ | NimbleProperties::NOTIFY,
     );
-    let mut battery_level_descriptor = battery_level_characteristic.lock().create_2904_descriptor();
-    battery_level_descriptor
-      .format(BLE2904Format::UINT8)
-      .namespace(1)
-      .unit(0x27ad);
+    battery_level_characteristic.lock().cpfd(Cpfd {
+      format: ChrFormat::Uint8,
+      exponent: 0,
+      unit: ChrUnit::Percentage,
+      name_space: 1,
+      description: 0,
+    });
 
     Self {
       device_info_service,
@@ -73,7 +74,6 @@ impl BLEHIDDevice {
       protocol_mode_characteristic,
       battery_service,
       battery_level_characteristic,
-      battery_level_descriptor,
     }
   }
 
diff --git a/src/server/cpfd.rs b/src/server/cpfd.rs
index fbfae10..20cba9e 100644
--- a/src/server/cpfd.rs
+++ b/src/server/cpfd.rs
@@ -1,7 +1,17 @@
-use esp_idf_svc::sys as esp_idf_sys;
 use num_enum::IntoPrimitive;
+use zerocopy_derive::{Immutable, IntoBytes, KnownLayout, TryFromBytes};
 
-#[derive(Copy, Clone, PartialEq, Eq, Debug, IntoPrimitive)]
+cfg_if::cfg_if! {
+  if #[cfg(cpfd)] {
+    use esp_idf_svc::sys as esp_idf_sys;
+  } else {
+    use super::cpfd_constants as esp_idf_sys;
+  }
+}
+
+#[derive(
+  Copy, Clone, PartialEq, Eq, Debug, IntoPrimitive, TryFromBytes, KnownLayout, IntoBytes, Immutable,
+)]
 #[repr(u8)]
 pub enum ChrFormat {
   Boolean = esp_idf_sys::BLE_GATT_CHR_FORMAT_BOOLEAN as _,
@@ -34,7 +44,9 @@ pub enum ChrFormat {
   Medasn1 = esp_idf_sys::BLE_GATT_CHR_FORMAT_MEDASN1 as _,
 }
 
-#[derive(Copy, Clone, PartialEq, Eq, Debug, IntoPrimitive)]
+#[derive(
+  Copy, Clone, PartialEq, Eq, Debug, IntoPrimitive, TryFromBytes, KnownLayout, IntoBytes, Immutable,
+)]
 #[repr(u16)]
 pub enum ChrUnit {
   /// Unitless
@@ -295,6 +307,8 @@ pub enum ChrUnit {
   VoltAmpere = esp_idf_sys::BLE_GATT_CHR_UNIT_VOLT_AMPERE as _,
 }
 
+#[derive(TryFromBytes, KnownLayout, IntoBytes, Immutable)]
+#[repr(packed)]
 pub struct Cpfd {
   /// Format of the value of this characteristic.
   pub format: ChrFormat,
diff --git a/src/server/cpfd_constants.rs b/src/server/cpfd_constants.rs
new file mode 100644
index 0000000..0ab3f05
--- /dev/null
+++ b/src/server/cpfd_constants.rs
@@ -0,0 +1,155 @@
+pub(crate) const BLE_GATT_CHR_FORMAT_BOOLEAN: u8 = 0x01;
+pub(crate) const BLE_GATT_CHR_FORMAT_UINT2: u8 = 0x02;
+pub(crate) const BLE_GATT_CHR_FORMAT_UINT4: u8 = 0x03;
+pub(crate) const BLE_GATT_CHR_FORMAT_UINT8: u8 = 0x04;
+pub(crate) const BLE_GATT_CHR_FORMAT_UINT12: u8 = 0x05;
+pub(crate) const BLE_GATT_CHR_FORMAT_UINT16: u8 = 0x06;
+pub(crate) const BLE_GATT_CHR_FORMAT_UINT24: u8 = 0x07;
+pub(crate) const BLE_GATT_CHR_FORMAT_UINT32: u8 = 0x08;
+pub(crate) const BLE_GATT_CHR_FORMAT_UINT48: u8 = 0x09;
+pub(crate) const BLE_GATT_CHR_FORMAT_UINT64: u8 = 0x0A;
+pub(crate) const BLE_GATT_CHR_FORMAT_UINT128: u8 = 0x0B;
+pub(crate) const BLE_GATT_CHR_FORMAT_SINT8: u8 = 0x0C;
+pub(crate) const BLE_GATT_CHR_FORMAT_SINT12: u8 = 0x0D;
+pub(crate) const BLE_GATT_CHR_FORMAT_SINT16: u8 = 0x0E;
+pub(crate) const BLE_GATT_CHR_FORMAT_SINT24: u8 = 0x0F;
+pub(crate) const BLE_GATT_CHR_FORMAT_SINT32: u8 = 0x10;
+pub(crate) const BLE_GATT_CHR_FORMAT_SINT48: u8 = 0x11;
+pub(crate) const BLE_GATT_CHR_FORMAT_SINT64: u8 = 0x12;
+pub(crate) const BLE_GATT_CHR_FORMAT_SINT128: u8 = 0x13;
+pub(crate) const BLE_GATT_CHR_FORMAT_FLOAT32: u8 = 0x14;
+pub(crate) const BLE_GATT_CHR_FORMAT_FLOAT64: u8 = 0x15;
+pub(crate) const BLE_GATT_CHR_FORMAT_MEDFLOAT16: u8 = 0x16;
+pub(crate) const BLE_GATT_CHR_FORMAT_MEDFLOAT32: u8 = 0x17;
+pub(crate) const BLE_GATT_CHR_FORMAT_UINT16_2: u8 = 0x18;
+pub(crate) const BLE_GATT_CHR_FORMAT_UTF8S: u8 = 0x19;
+pub(crate) const BLE_GATT_CHR_FORMAT_UTF16S: u8 = 0x1A;
+pub(crate) const BLE_GATT_CHR_FORMAT_STRUCT: u8 = 0x1B;
+pub(crate) const BLE_GATT_CHR_FORMAT_MEDASN1: u8 = 0x1C;
+
+pub(crate) const BLE_GATT_CHR_UNIT_UNITLESS: u16 = 0x2700; /* Unitless */
+pub(crate) const BLE_GATT_CHR_UNIT_METRE: u16 = 0x2701; /* Length */
+pub(crate) const BLE_GATT_CHR_UNIT_KILOGRAM: u16 = 0x2702; /* Mass */
+pub(crate) const BLE_GATT_CHR_UNIT_SECOND: u16 = 0x2703; /* Time */
+pub(crate) const BLE_GATT_CHR_UNIT_AMPERE: u16 = 0x2704; /* Electric Current */
+pub(crate) const BLE_GATT_CHR_UNIT_KELVIN: u16 = 0x2705; /* Thermodynamic Temperature */
+pub(crate) const BLE_GATT_CHR_UNIT_MOLE: u16 = 0x2706; /* Amount Of Substance */
+pub(crate) const BLE_GATT_CHR_UNIT_CANDELA: u16 = 0x2707; /* Luminous Intensity */
+pub(crate) const BLE_GATT_CHR_UNIT_SQUARE_METRES: u16 = 0x2710; /* Area */
+pub(crate) const BLE_GATT_CHR_UNIT_CUBIC_METRES: u16 = 0x2711; /* Volume */
+pub(crate) const BLE_GATT_CHR_UNIT_METRES_PER_SECOND: u16 = 0x2712; /* Velocity */
+pub(crate) const BLE_GATT_CHR_UNIT_METRES_PER_SECOND_SQUARED: u16 = 0x2713; /* Acceleration */
+pub(crate) const BLE_GATT_CHR_UNIT_RECIPROCAL_METRE: u16 = 0x2714; /* Wavenumber */
+pub(crate) const BLE_GATT_CHR_UNIT_KILOGRAM_PER_CUBIC_METRE_DENSITY: u16 = 0x2715; /* Density */
+pub(crate) const BLE_GATT_CHR_UNIT_KILOGRAM_PER_SQUARE_METRE: u16 = 0x2716; /* Surface Density */
+pub(crate) const BLE_GATT_CHR_UNIT_CUBIC_METRE_PER_KILOGRAM: u16 = 0x2717; /* Specific Volume */
+pub(crate) const BLE_GATT_CHR_UNIT_AMPERE_PER_SQUARE_METRE: u16 = 0x2718; /* Current Density */
+pub(crate) const BLE_GATT_CHR_UNIT_AMPERE_PER_METRE: u16 = 0x2719; /* Magnetic Field Strength */
+pub(crate) const BLE_GATT_CHR_UNIT_MOLE_PER_CUBIC_METRE: u16 = 0x271A; /* Amount Concentration */
+pub(crate) const BLE_GATT_CHR_UNIT_KILOGRAM_PER_CUBIC_METRE_MASS_CONC: u16 = 0x271B; /* Mass Concentration */
+pub(crate) const BLE_GATT_CHR_UNIT_CANDELA_PER_SQUARE_METRE: u16 = 0x271C; /* Luminance */
+pub(crate) const BLE_GATT_CHR_UNIT_REFRACTIVE_INDEX: u16 = 0x271D; /* Refractive Index */
+pub(crate) const BLE_GATT_CHR_UNIT_RELATIVE_PERMEABILITY: u16 = 0x271E; /* Relative Permeability */
+pub(crate) const BLE_GATT_CHR_UNIT_RADIAN: u16 = 0x2720; /* Plane Angle */
+pub(crate) const BLE_GATT_CHR_UNIT_STERADIAN: u16 = 0x2721; /* Solid Angle */
+pub(crate) const BLE_GATT_CHR_UNIT_HERTZ: u16 = 0x2722; /* Frequency */
+pub(crate) const BLE_GATT_CHR_UNIT_NEWTON: u16 = 0x2723; /* Force */
+pub(crate) const BLE_GATT_CHR_UNIT_PASCAL: u16 = 0x2724; /* Pressure */
+pub(crate) const BLE_GATT_CHR_UNIT_JOULE: u16 = 0x2725; /* Energy */
+pub(crate) const BLE_GATT_CHR_UNIT_WATT: u16 = 0x2726; /* Power */
+pub(crate) const BLE_GATT_CHR_UNIT_COULOMB: u16 = 0x2727; /* Electric Charge */
+pub(crate) const BLE_GATT_CHR_UNIT_VOLT: u16 = 0x2728; /* Electric Potential Difference */
+pub(crate) const BLE_GATT_CHR_UNIT_FARAD: u16 = 0x2729; /* Capacitance */
+pub(crate) const BLE_GATT_CHR_UNIT_OHM: u16 = 0x272A; /* Electric Resistance */
+pub(crate) const BLE_GATT_CHR_UNIT_SIEMENS: u16 = 0x272B; /* Electric Conductance */
+pub(crate) const BLE_GATT_CHR_UNIT_WEBER: u16 = 0x272C; /* Magnetic Flux */
+pub(crate) const BLE_GATT_CHR_UNIT_TESLA: u16 = 0x272D; /* Magnetic Flux Density */
+pub(crate) const BLE_GATT_CHR_UNIT_HENRY: u16 = 0x272E; /* Inductance */
+pub(crate) const BLE_GATT_CHR_UNIT_DEGREE_CELSIUS: u16 = 0x272F; /* celsius Temperature */
+pub(crate) const BLE_GATT_CHR_UNIT_LUMEN: u16 = 0x2730; /* Luminous Flux */
+pub(crate) const BLE_GATT_CHR_UNIT_LUX: u16 = 0x2731; /* Illuminance */
+pub(crate) const BLE_GATT_CHR_UNIT_BECQUEREL: u16 = 0x2732; /* Activity Referred To A Radionuclide */
+pub(crate) const BLE_GATT_CHR_UNIT_GRAY: u16 = 0x2733; /* Absorbed Dose */
+pub(crate) const BLE_GATT_CHR_UNIT_SIEVERT: u16 = 0x2734; /* Dose Equivalent */
+pub(crate) const BLE_GATT_CHR_UNIT_KATAL: u16 = 0x2735; /* Catalytic Activity */
+pub(crate) const BLE_GATT_CHR_UNIT_PASCAL_SECOND: u16 = 0x2740; /* Dynamic Viscosity */
+pub(crate) const BLE_GATT_CHR_UNIT_NEWTON_METRE: u16 = 0x2741; /* Moment Of Force */
+pub(crate) const BLE_GATT_CHR_UNIT_NEWTON_PER_METRE: u16 = 0x2742; /* Surface Tension */
+pub(crate) const BLE_GATT_CHR_UNIT_RADIAN_PER_SECOND: u16 = 0x2743; /* Angular Velocity */
+pub(crate) const BLE_GATT_CHR_UNIT_RADIAN_PER_SECOND_SQUARED: u16 = 0x2744; /* Angular Acceleration */
+pub(crate) const BLE_GATT_CHR_UNIT_WATT_PER_SQUARE_METRE_HEAT: u16 = 0x2745; /* Heat Flux Density */
+pub(crate) const BLE_GATT_CHR_UNIT_JOULE_PER_KELVIN: u16 = 0x2746; /* Heat Capacity */
+pub(crate) const BLE_GATT_CHR_UNIT_JOULE_PER_KILOGRAM_KELVIN: u16 = 0x2747; /* Specific Heat Capacity */
+pub(crate) const BLE_GATT_CHR_UNIT_JOULE_PER_KILOGRAM: u16 = 0x2748; /* Specific Energy */
+pub(crate) const BLE_GATT_CHR_UNIT_WATT_PER_METRE_KELVIN: u16 = 0x2749; /* Thermal Conductivity */
+pub(crate) const BLE_GATT_CHR_UNIT_JOULE_PER_CUBIC_METRE: u16 = 0x274A; /* Energy Density */
+pub(crate) const BLE_GATT_CHR_UNIT_VOLT_PER_METRE: u16 = 0x274B; /* Electric Field Strength */
+pub(crate) const BLE_GATT_CHR_UNIT_COULOMB_PER_CUBIC_METRE: u16 = 0x274C; /* Electric Charge Density */
+pub(crate) const BLE_GATT_CHR_UNIT_COULOMB_PER_SQUARE_METRE_CHARGE: u16 = 0x274D; /* Surface Charge Density */
+pub(crate) const BLE_GATT_CHR_UNIT_COULOMB_PER_SQUARE_METRE_FLUX: u16 = 0x274E; /* Electric Flux Density */
+pub(crate) const BLE_GATT_CHR_UNIT_FARAD_PER_METRE: u16 = 0x274F; /* Permittivity */
+pub(crate) const BLE_GATT_CHR_UNIT_HENRY_PER_METRE: u16 = 0x2750; /* Permeability */
+pub(crate) const BLE_GATT_CHR_UNIT_JOULE_PER_MOLE: u16 = 0x2751; /* Molar Energy */
+pub(crate) const BLE_GATT_CHR_UNIT_JOULE_PER_MOLE_KELVIN: u16 = 0x2752; /* Molar Entropy */
+pub(crate) const BLE_GATT_CHR_UNIT_COULOMB_PER_KILOGRAM: u16 = 0x2753; /* Exposure */
+pub(crate) const BLE_GATT_CHR_UNIT_GRAY_PER_SECOND: u16 = 0x2754; /* Absorbed Dose Rate */
+pub(crate) const BLE_GATT_CHR_UNIT_WATT_PER_STERADIAN: u16 = 0x2755; /* Radiant Intensity */
+pub(crate) const BLE_GATT_CHR_UNIT_WATT_PER_SQUARE_METRE_STERADIAN: u16 = 0x2756; /* Radiance */
+pub(crate) const BLE_GATT_CHR_UNIT_KATAL_PER_CUBIC_METRE: u16 = 0x2757; /* Catalytic Activity Concentration */
+pub(crate) const BLE_GATT_CHR_UNIT_MINUTE: u16 = 0x2760; /* Time */
+pub(crate) const BLE_GATT_CHR_UNIT_HOUR: u16 = 0x2761; /* Time */
+pub(crate) const BLE_GATT_CHR_UNIT_DAY: u16 = 0x2762; /* Time */
+pub(crate) const BLE_GATT_CHR_UNIT_DEGREE: u16 = 0x2763; /* Plane Angle */
+pub(crate) const BLE_GATT_CHR_UNIT_MINUTE_ANGLE: u16 = 0x2764; /* Plane Angle */
+pub(crate) const BLE_GATT_CHR_UNIT_SECOND_ANGLE: u16 = 0x2765; /* Plane Angle */
+pub(crate) const BLE_GATT_CHR_UNIT_HECTARE: u16 = 0x2766; /* Area */
+pub(crate) const BLE_GATT_CHR_UNIT_LITRE: u16 = 0x2767; /* Volume */
+pub(crate) const BLE_GATT_CHR_UNIT_TONNE: u16 = 0x2768; /* Mass */
+pub(crate) const BLE_GATT_CHR_UNIT_BAR: u16 = 0x2780; /* Pressure */
+pub(crate) const BLE_GATT_CHR_UNIT_MILLIMETRE_OF_MERCURY: u16 = 0x2781; /* Pressure */
+pub(crate) const BLE_GATT_CHR_UNIT_ANGSTROM: u16 = 0x2782; /* Length */
+pub(crate) const BLE_GATT_CHR_UNIT_NAUTICAL_MILE: u16 = 0x2783; /* Length */
+pub(crate) const BLE_GATT_CHR_UNIT_BARN: u16 = 0x2784; /* Area */
+pub(crate) const BLE_GATT_CHR_UNIT_KNOT: u16 = 0x2785; /* Velocity */
+pub(crate) const BLE_GATT_CHR_UNIT_NEPER: u16 = 0x2786; /* Logarithmic Radio Quantity */
+pub(crate) const BLE_GATT_CHR_UNIT_BEL: u16 = 0x2787; /* Logarithmic Radio Quantity */
+pub(crate) const BLE_GATT_CHR_UNIT_YARD: u16 = 0x27A0; /* Length */
+pub(crate) const BLE_GATT_CHR_UNIT_PARSEC: u16 = 0x27A1; /* Length */
+pub(crate) const BLE_GATT_CHR_UNIT_INCH: u16 = 0x27A2; /* Length */
+pub(crate) const BLE_GATT_CHR_UNIT_FOOT: u16 = 0x27A3; /* Length */
+pub(crate) const BLE_GATT_CHR_UNIT_MILE: u16 = 0x27A4; /* Length */
+pub(crate) const BLE_GATT_CHR_UNIT_POUND_FORCE_PER_SQUARE_INCH: u16 = 0x27A5; /* Pressure */
+pub(crate) const BLE_GATT_CHR_UNIT_KILOMETRE_PER_HOUR: u16 = 0x27A6; /* Velocity */
+pub(crate) const BLE_GATT_CHR_UNIT_MILE_PER_HOUR: u16 = 0x27A7; /* Velocity */
+pub(crate) const BLE_GATT_CHR_UNIT_REVOLUTION_PER_MINUTE: u16 = 0x27A8; /* Angular Velocity */
+pub(crate) const BLE_GATT_CHR_UNIT_GRAM_CALORIE: u16 = 0x27A9; /* Energy */
+pub(crate) const BLE_GATT_CHR_UNIT_KILOGRAM_CALORIE: u16 = 0x27AA; /* Energy */
+pub(crate) const BLE_GATT_CHR_UNIT_KILOWATT_HOUR: u16 = 0x27AB; /* Energy */
+pub(crate) const BLE_GATT_CHR_UNIT_DEGREE_FAHRENHEIT: u16 = 0x27AC; /* Thermodynamic Temperature */
+pub(crate) const BLE_GATT_CHR_UNIT_PERCENTAGE: u16 = 0x27AD; /* Percentage */
+pub(crate) const BLE_GATT_CHR_UNIT_PER_MILLE: u16 = 0x27AE; /* Per Mille */
+pub(crate) const BLE_GATT_CHR_UNIT_BEATS_PER_MINUTE: u16 = 0x27AF; /* Period */
+pub(crate) const BLE_GATT_CHR_UNIT_AMPERE_HOURS: u16 = 0x27B0; /* Electric Charge */
+pub(crate) const BLE_GATT_CHR_UNIT_MILLIGRAM_PER_DECILITRE: u16 = 0x27B1; /* Mass Density */
+pub(crate) const BLE_GATT_CHR_UNIT_MILLIMOLE_PER_LITRE: u16 = 0x27B2; /* Mass Density */
+pub(crate) const BLE_GATT_CHR_UNIT_YEAR: u16 = 0x27B3; /* Time */
+pub(crate) const BLE_GATT_CHR_UNIT_MONTH: u16 = 0x27B4; /* Time */
+pub(crate) const BLE_GATT_CHR_UNIT_COUNT_PER_CUBIC_METRE: u16 = 0x27B5; /* Concentration */
+pub(crate) const BLE_GATT_CHR_UNIT_WATT_PER_SQUARE_METRE_IRRADIANCE: u16 = 0x27B6; /* Irradiance */
+pub(crate) const BLE_GATT_CHR_UNIT_PER_KILOGRAM_PER_MINUTE: u16 = 0x27B7; /* Milliliter */
+pub(crate) const BLE_GATT_CHR_UNIT_POUND: u16 = 0x27B8; /* Mass */
+pub(crate) const BLE_GATT_CHR_UNIT_METABOLIC_EQUIVALENT: u16 = 0x27B9; /* Metabolic Equivalent */
+pub(crate) const BLE_GATT_CHR_UNIT_PER_MINUTE_STEP: u16 = 0x27BA; /* Step */
+pub(crate) const BLE_GATT_CHR_UNIT_PER_MINUTE_STROKE: u16 = 0x27BC; /* Stroke */
+pub(crate) const BLE_GATT_CHR_UNIT_KILOMETRE_PER_MINUTE: u16 = 0x27BD; /* Pace */
+pub(crate) const BLE_GATT_CHR_UNIT_LUMEN_PER_WATT: u16 = 0x27BE; /* Luminous Efficacy */
+pub(crate) const BLE_GATT_CHR_UNIT_LUMEN_HOUR: u16 = 0x27BF; /* Luminous Energy */
+pub(crate) const BLE_GATT_CHR_UNIT_LUX_HOUR: u16 = 0x27C0; /* Luminous Exposure */
+pub(crate) const BLE_GATT_CHR_UNIT_GRAM_PER_SECOND: u16 = 0x27C1; /* Mass Flow */
+pub(crate) const BLE_GATT_CHR_UNIT_LITRE_PER_SECOND: u16 = 0x27C2; /* Volume Flow */
+pub(crate) const BLE_GATT_CHR_UNIT_DECIBEL: u16 = 0x27C3; /* Sound Pressure */
+pub(crate) const BLE_GATT_CHR_UNIT_PARTS_PER_MILLION: u16 = 0x27C4; /* Concentration */
+pub(crate) const BLE_GATT_CHR_UNIT_PARTS_PER_BILLION: u16 = 0x27C5; /* Concentration */
+pub(crate) const BLE_GATT_CHR_UNIT_MILLIGRAM_PER_DECILITRE_PER_MINUTE: u16 = 0x27C6; /* Mass Density Rate */
+pub(crate) const BLE_GATT_CHR_UNIT_KILOVOLT_AMPERE_HOUR: u16 = 0x27C7; /* Electrical Apparent Energy */
+pub(crate) const BLE_GATT_CHR_UNIT_VOLT_AMPERE: u16 = 0x27C8; /* Electrical Apparent Power */
diff --git a/src/server/mod.rs b/src/server/mod.rs
index 3ceb4a5..e4df6fa 100644
--- a/src/server/mod.rs
+++ b/src/server/mod.rs
@@ -1,9 +1,6 @@
 mod att_value;
 pub use self::att_value::AttValue;
 
-mod ble_2904;
-pub use self::ble_2904::*;
-
 mod ble_advertisement_data;
 pub use self::ble_advertisement_data::BLEAdvertisementData;
 
@@ -34,8 +31,9 @@ pub use self::ble_server::BLEServer;
 mod ble_service;
 pub use self::ble_service::BLEService;
 
-#[cfg(cpfd)]
 pub mod cpfd;
+#[cfg(not(cpfd))]
+mod cpfd_constants;
 
 pub mod hid;