IRWIN Impact Performance Series Socket Extensions provide extended reach and easier access to hard to reach spaces. IRWIN socket extensions 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" socket extension connects 3/8" square drive drills or accessories to 3/8" square drive sockets or accessories and the 1/2" socket extension connects 1/2" square drive dills or accessories to 1/2" square drive sockets or accessories.