diff --git a/src/Draw/Draw_UnitCommands.cxx b/src/Draw/Draw_UnitCommands.cxx
index 07937c5ea9..217f9295cf 100644
--- a/src/Draw/Draw_UnitCommands.cxx
+++ b/src/Draw/Draw_UnitCommands.cxx
@@ -127,10 +127,10 @@ static Standard_Integer converttoMDTV
 //purpose  : 
 //=======================================================================
 
-static Standard_Integer unit(Draw_Interpretor& , Standard_Integer n, const char** a)
+static Standard_Integer unit(Draw_Interpretor& di, Standard_Integer n, const char** a)
 {
   if(n == 4) {
-    cout << Units::Convert(Draw::Atof(a[1]), a[2], a[3]) << endl;
+    di << Units::Convert(Draw::Atof(a[1]), a[2], a[3]);
     return 0;
   }
   else
diff --git a/src/UnitsAPI/Units.dat b/src/UnitsAPI/Units.dat
index 58581719d6..f797fdf710 100755
--- a/src/UnitsAPI/Units.dat
+++ b/src/UnitsAPI/Units.dat
@@ -41,7 +41,7 @@ micron                                             
 mille                                              mille                            1852                 m
 light year                                         Al                                  9.46053E+15       m
 
-inch                                               in.                                25.40001969E-03    m
+inch                                               in.                                 0.0254            m
                                                    in
 caliber                                            caliber                             1                 in.
 foot                                               ft.                                12                 in
@@ -51,7 +51,7 @@ yard                                               yd.
                                                    yd
 
 statute mile                                       stat.mile                        1760                 yd.
-nautical mile                                      naut.mile                        6080                 ft.
+nautical mile                                      naut.mile                        1852                 m
 ....................................................................................................................................
                                                  M         L         T         I         K         N         J         P         S
 TIME                                             0         0         1         0         0         0         0         0         0
diff --git a/src/UnitsMethods/UnitsMethods.cxx b/src/UnitsMethods/UnitsMethods.cxx
index f4eb8cfdf4..f73b3ce965 100644
--- a/src/UnitsMethods/UnitsMethods.cxx
+++ b/src/UnitsMethods/UnitsMethods.cxx
@@ -414,17 +414,17 @@ void UnitsMethods::SetCasCadeLengthUnit (const Standard_Integer unit)
 Standard_Real UnitsMethods::GetLengthFactorValue (const Standard_Integer par) 
 {
   switch ( par ) {
-  case  1 : return 25.4;
-  case  2 : return 1.;
+  case  1 : return 25.4; // inch
+  case  2 : return 1.; // millimeter
   
-  case  4 : return 304.8;
-  case  5 : return 1609270.;
-  case  6 : return 1000.;
-  case  7 : return 1000000.;
-  case  8 : return 0.0254;
-  case  9 : return 0.001;
-  case 10 : return 10.;
-  case 11 : return 0.0000254;
+  case  4 : return 304.8; // foot
+  case  5 : return 1609344.; // mile
+  case  6 : return 1000.; // meter
+  case  7 : return 1000000.; // kilometer
+  case  8 : return 0.0254; // mil (0.001 inch)
+  case  9 : return 0.001; // micron
+  case 10 : return 10.; // centimeter
+  case 11 : return 0.0000254; // microinch
   default : return 1.;
   }
 }