With a 6-point opening, the TEKTON 1/2 in. Drive x 13/16 in. Spark Plug Socket snugly fits the hex nut of the spark plug, allowing you to apply maximum torque and loosen stubborn, heat-seized plugs without slipping. Its advanced design grips the flat sides of the hex nut, rather than just the corners, to prevent round-off under stress. For sure-handed removal and installation, a rubber grommet inside holds on to the neck of the spark plug, keeping it secured in place and engaged with the socket.