Milwaukee Fastback ring and

This is a TPU ring designed to go over the ring on the hex driver to the Milwaukee Fastback 6-in-1 utility knife and ¼ inch driver. The ring often will get caught, and dislodge the 1/8 in. BB or ball bearing. Placing a flexible ring like this over the metal ring will help prevent this from happening so you don't lose your bits.

TPU is a very flexible filament that should stretch just a little to go over and hold everything together. Other filaments may not work with this design.