Those of you who have older Sizzix lever-type presses will probably need to add some shims in order to use our dies, which are thinner than the Sizzix dies. The plastic pieces in this shim set have three different thicknesses, and there are two of the thinnest ones. These can be use individually or in combination to make the thickness just right for your press. You can use these shims with the wider roll-through machines as well.