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. Individual screws not available separately. Features : #6-40 Fillister Head (3/8, 1/2) #6-40 Oval Head (1/4, 3/8) #6-48 Fillister Head (1/4, 3/8, 9/16) #6-48 Oval Head (1/4, 3/8) #8-40 Fillister Head (1/4, 3/8, 1/2) #8-40 Oval Head (1/4, 1/2)