diff --git a/Filtered_kernel/include/CGAL/Filtered_kernel/internal/Static_filters/tools.h b/Filtered_kernel/include/CGAL/Filtered_kernel/internal/Static_filters/tools.h
index 6aab973bd804..6b7de531f765 100644
--- a/Filtered_kernel/include/CGAL/Filtered_kernel/internal/Static_filters/tools.h
+++ b/Filtered_kernel/include/CGAL/Filtered_kernel/internal/Static_filters/tools.h
@@ -19,6 +19,8 @@
 
 namespace CGAL {
 
+class Filtered_rational;
+
 template < typename ET >
 class Lazy_exact_nt;
 
@@ -233,6 +235,7 @@ inline bool fit_in_double(const int& i, double& r) { r = i; return true; }
 template < typename ET >
 inline bool fit_in_double(const Lazy_exact_nt<ET>&, double&);
 
+inline bool fit_in_double(const Filtered_rational&, double&);
 
 // Auxiliary functor, to get the approximation of a kernel object:
 //   - for a Point_3 of the Lazy_kernel<...>, one needs to call approx(),
diff --git a/Number_types/include/CGAL/Filtered_rational.h b/Number_types/include/CGAL/Filtered_rational.h
new file mode 100644
index 000000000000..50247efe9eff
--- /dev/null
+++ b/Number_types/include/CGAL/Filtered_rational.h
@@ -0,0 +1,167 @@
+#ifndef CGAL_FILTERED_RATIONAL_H
+
+#include <CGAL/Exact_rational.h>
+#include <CGAL/Interval_nt.h>
+
+namespace CGAL {
+
+struct Filtered_rational : boost::totally_ordered1<Filtered_rational
+                                                     //#ifdef _MSC_VER
+                 , boost::ordered_ring_operators2<Filtered_rational, int
+                 , boost::ordered_ring_operators2<Filtered_rational, double
+                 > >
+                                                     //#endif
+                 >
+{
+  Interval_nt<> i;
+  Exact_rational rat;
+
+  Filtered_rational()
+  {}
+
+  Filtered_rational(int d)
+    : i(d), rat(d)
+  {}
+
+  Filtered_rational(double d)
+    : i(d), rat(d)
+  {}
+
+
+  Filtered_rational(const Interval_nt<>& i, const Exact_rational& rat)
+      : i(i), rat(rat)
+  {}
+
+ Filtered_rational operator-() const
+ {
+   return Filtered_rational(-i, -rat);
+ }
+
+ Filtered_rational operator+(const Filtered_rational& b) const
+ {
+     return Filtered_rational(i + b.i, rat + b.rat);
+ }
+
+
+ Filtered_rational operator-(const Filtered_rational& b) const
+ {
+     return Filtered_rational(i - b.i, rat - b.rat);
+ }
+
+ Filtered_rational operator*(const Filtered_rational& b) const
+ {
+     return Filtered_rational(i * b.i, rat * b.rat);
+ }
+
+ Filtered_rational operator/(const Filtered_rational& b) const
+ {
+     return Filtered_rational(i / b.i, rat / b.rat);
+ }
+
+
+
+  Filtered_rational& operator+=(const Filtered_rational &a) { return *this = *this + a; }
+  Filtered_rational& operator-=(const Filtered_rational &a) { return *this = *this - a; }
+  Filtered_rational& operator*=(const Filtered_rational &a) { return *this = *this * a; }
+  Filtered_rational& operator/=(const Filtered_rational &a) { return *this = *this / a; }
+
+};
+
+
+template <> class Real_embeddable_traits< Filtered_rational >
+  : public INTERN_RET::Real_embeddable_traits_base< Filtered_rational, CGAL::Tag_true > {
+  public:
+
+    class Sgn
+      : public CGAL::cpp98::unary_function< Type, ::CGAL::Sign > {
+      public:
+        ::CGAL::Sign operator()( const Type& x ) const {
+          return sign(x);
+        }
+    };
+};
+
+
+
+bool operator==(const Filtered_rational& a,
+                const Filtered_rational& b)
+  {
+    Uncertain<bool> u = a.i == b.i;
+    if(is_indeterminate(u)){
+      return a.rat == b.rat;
+    }
+    return make_certain(u);
+  }
+
+
+
+bool operator<(const Filtered_rational& a,
+                const Filtered_rational& b)
+  {
+    Uncertain<bool> u = a.i < b.i;
+    if(is_indeterminate(u)){
+      return a.rat < b.rat;
+    }
+    return make_certain(u);
+  }
+
+  Sign sign(const Filtered_rational& a)
+  {
+    Uncertain<Sign> u = sign(a.i);
+     if(is_indeterminate(u)){
+       return CGAL::sign(a.rat);
+    }
+    return make_certain(u);
+  }
+
+  Sign compare(const Filtered_rational& a, const Filtered_rational& b){
+    Uncertain<Sign> u = compare(a.i, b.i);
+     if(is_indeterminate(u)){
+       return compare(a.rat, b.rat);
+    }
+    return make_certain(u);
+  }
+
+  Filtered_rational square(const Filtered_rational& a)
+  {
+    return Filtered_rational(square(a.i), square(a.rat));
+  }
+
+  std::pair<double,double> to_interval(const Filtered_rational& b)
+{
+  return std::make_pair(b.i.inf(), b.i.sup());
+}
+
+  double to_double(const Filtered_rational& b)
+  {
+    return to_double(b.i);
+  }
+
+
+  std::ostream& operator<<(std::ostream& os, const Filtered_rational& )
+  {
+    return os;
+  }
+
+  std::istream& operator>>(std::istream& is, const Filtered_rational& )
+  {
+    return is;
+  }
+
+  namespace internal {
+
+      inline bool fit_in_double(const Filtered_rational& fr, double& d)
+      {
+          return fit_in_double(fr.i, d);
+      }
+  }
+CGAL_DEFINE_COERCION_TRAITS_FOR_SELF(Filtered_rational)
+CGAL_DEFINE_COERCION_TRAITS_FROM_TO(short    ,Filtered_rational)
+CGAL_DEFINE_COERCION_TRAITS_FROM_TO(int      ,Filtered_rational)
+CGAL_DEFINE_COERCION_TRAITS_FROM_TO(long     ,Filtered_rational)
+CGAL_DEFINE_COERCION_TRAITS_FROM_TO(float    ,Filtered_rational)
+CGAL_DEFINE_COERCION_TRAITS_FROM_TO(double   ,Filtered_rational)
+
+} // namespace CGAL
+
+#endif