1/4" and 10mm Hex Bit Ratchets with 1/4" and 3/8" Inserts. Works with all 1/4ââ bits and 10mm fasteners. Includes 1/4ââ & 3/8ââ square drive inserts. Reversible 72-tooth gear head requires only 5 degrees of sweep, opposite end has reversible 60-tooth gear head and requires only 6 degrees of sweep.