Master Mechanic, 7 Piece, Screwdriver Bit Set, Includes #1, #2, #3 Phillips Insert Bit Tip, #6-8, #8-10, #10-12 Slotted Insert Bit Tip & Bit Tip Holder. Slotted Bits Full Blade Width & Extra Thickness Fill Slot Reducing Slipping & Breakage, Maximum Durability Shock Resistant Tool Steel.