Industrial quality bits are manufactured to withstand the same high-torque use as Irwin power bits; 1/4" hex shank. Includes (1) one each: #1PH/6-8 Sl., #2PH/8-10 Sl., #3PH/10-12 Sl. INSERT BIT SETS Lgth In=2-3/8 3-PIECES DOUBLE-ENDED PHILLIPS/SLOTTED