Shims
4 pieces;
0,003" = approx. 0,076 mm
0,010" = approx. 0,254 mm

Note!
Shims are not available anymore.

Alternative: There's an alterative called Lamiblock that consists of 12 layers of steel or brass with a total thickness of 1 mm. Lamiblock is available in different sizes, for example 100x100 mm. As it is really expensive, you are well advised not to loose your original shims.