Performance Tool 3/8" Drive 6 Point SAE Standard Spark Plug Socket part number W38163. SAE size 3/4". External Hex 7/8". Overall Length 2 9/16". Chrome vanadium constructed. Recessed edges. Fully polished. Lifetime warranty. Caution: DO NOT use chrome sockets or drive with impact or power tools. Pull hand tools toward you. DO NOT push. Maintain your balance. Keep tools clean.