Laser 7295 3 Piece Thin Wall Spark Plug Socket Set Features and Benefits:Thin walled spark plug sockets are required for access in many modern enginesSizes: 14mm (O.D 18mm), 16mm (O.D. 20.4mm) 18mm (O.D 23mm)Length 63mm x 12 point (Bi-Hex) profile3/8″DManufactured from Chrome Vanadium with rubber inserts