Eighteen incredibly thin bits to fit the extra-narrow screw slots often encountered in the gun shop. Take great care when using these bits. The blade MUST fill the slot from side-to-side and edge-to-edge or it will most certainly break on a firmly seated screw. Freeze spray, heat, penetrating oil, a few taps, regrinding the bit for an even better fit - all these tricks can help give success. Bits Inluded in Kit #120-1 #120-2 #150-1 #150-2 #180-1 #180-2 #210-1 #210-2 #240-1 #240-2 #270-1 #270-2 #300-1 #300-2 #340-1 #340-2 #360-1 #360-2 Mfg: Brownells