These difficult to find screws are favored non-slip replacements for slotted screws. Packaged in a handy storage box with individual compartments for each size screw. Includes tweezers and a thread size gauge, which also doubles as a shortening jig used to grind a screw to a shorter length. Save time and money with the Master Gunsmith Hex Head Ring & Base Screw Kit, as it comes stocked with everything a gunsmith would need to replace slotted screws.