Set of 3 includes: 3⁄16", ¼" & 5⁄16" tips
Normal screwdrivers for slotted screws are tapered, which makes it easy to slot them in quickly but means that they only contact the slot at the top corners. A gunsmiths screwdriver is hollow ground with a parallel tip that engages fully with the slot in the screw.
Slower, a little, but much less likely to marr the screw head. Hardened, polished and lacquered blades, stained beech handle with knurled brass ferrule.