Spark plugs are a unique. You need a strong tool to release stubborn stuck plugs yet a soft touch so you don’t do any damage. The Powerbuilt 3/8-inch Drive 5/8-inch Spark Plug Socket is strong as well as protective of the spark plugs. The premium Chrome Vanadium steel socket has a mirror polished chrome finish for durability yet has a innovative rubber insert to protect the spark plugs and center hole punched for added work depth. The sleek chrome finish is enhanced with an easy to read size marking that is forged into the metal socket. Exclusive to Powerbuilt, precision chamfered Z-Drive 6-point hex faces easily guide the sockets on to fasteners and allow for a more solid grip on the flat surfaces to prevent damage or rounding.