IRWIN Impact Performance Series Socket Reducers make smaller square drive sockets and accessories compatible with 3/8" or 1/2" square drive drills or accessories. IRWIN square drive reducers are manufactured with heavy-duty chrome molybdenum steel for maximum durability and long life with impact drivers. Plus, they have a black oxide finish that resists corrosion and increases the life of the tool. The 3/8" square drive reducer connects 3/8" square drive drills or accessories to 1/4" square drive sockets or accessories and the 1/2" socket reducer connects 1/2" square drive dills or accessories to 3/8" square drive sockets or accessories.