1. The sleeve is made of the thinnest possible material.2. The stamp will not cut unless you apply it to concrete which will damage the stamp even after a few uses. A puncher is enough to make a mark telling you where to cut.3. 103 pcs mainly consists of 3 bushing installation tools and the bushing kit itself.4. A set of 100 bushings won't fit 1 to 1. I have more washers than the main bushing itself so basically I only have 37 pairs instead of 50 pairs. more expensive much better quality.