These ModelCraft keyhole saw blades fit perfectly in the Model Craft No. 2 knife handle and the Modelcraft 8 piece saw set. They are compatible with the No. 2 and No. 5 plastic handles from other manufacturers. These 60mm long blades have 24tpi for exceptionally fine cuts. When fitted into the knife handle, you can make delicate cuts in balsa, softwood, cardboard, plastic or foam. The blade tapers from 1mm at the tip to 4mm at its widest.