16mm, 18mm & 21mm Spark Plug Socket allows you to remove and replace spark plugs as easily as possible. Made of durable, heat-treated, chrome vanadium steel, this spark plug socket has Chrome plating for easy cleanup and a pro look in addition to its 360 degrees swivel action for maximum flexibility. Package Includes: 1 x Spark Plug 1 x 16mm socket 1 x 18mm socket 1 x 21mm socket