3/8-inch (F) x 1/4-inch (M) Allen key 3 pcs.

【DIMENSIONS】. Connect 3/8" (F) drive tools to 1/4" (M) drive sockets.
【CHROME-MOLYBDENUM STEEL】. Black chrome-molybdenum steel provides excellent durability and strength for any impact movement.
【SAFE HANDLE】. Chamfered ends and spring-loaded ball catch provide a secure grip on the sockets and prevent them from falling out.
【PRATIQUE】. Restraining notches on the ends of the gears hold ratchets and extensions, making them ideal for any industrial, mechanical or construction work.
【ROUNDED CORNERS】. Rounded angles inside the gears avoid stress concentrations that can cause cracks.