Milwaukee 3/8" Drive 18MM Spark Plug Socket is designed with a durable dual-material rubber retainer that ensures a more secure fit within the socket while holding spark plugs firmly to prevent dropping or damage. The precision knurling on the outside of the socket better control when hand tightening or loosening spark plugs. Both the socket and retainer are resistant to harsh chemicals commonly found in garages, making them reliable for tough working conditions. Easy-to-read stamped size markings help quickly identify the socket size, and the external hex at the base fits a 20mm wrench for added control. This spark plug socket is backed by Milwaukee’s Lifetime , ensuring long-lasting performance and durability. Model Number: 48-22-9556