The MILWAUKEE 3/8in Drive 5/8in 6 Point Magnetic Spark Plug Socket features an amplified rare earth magnetic retainer that balances a secure fit with smooth removal of the spark plug from the socket. A precision knurling on the outside of the socket allows for better control when hand tightening or loosening. Both the socket and retainer withstand harsh chemicals commonly found in the garage. Stamped size markings make it easy to identify the size of the socket. The external hex at the base of the socket fits an 11/16 wrench for added control. Milwaukee Spark Plug Sockets are backed with a Lifetime Guarantee.