Includes an internal magnet to securely hold the spark plug in place during installation or removal. Thin wall design is intended for use when there is limited clearance for the spark plug. A universal joint with a rotating 360 head which is ideal when space is limited, allowing easier access than a standard socket. Standard depth socket 12-point 3/8 SQ drive 16mm. Manufactured from Chrome Vanadium that is hardened and heat treated for strength and durability. Knurled for easy grip with oily hands.