Made of premium carbon steel, high strength and long durability. Not easy to slick, deep thread, no deformation, smooth thread, high precision. High hardness and low abrasion. locking-design allows it lock the the screw into the threaded hole,avoiding sliding wire. Greatly improve strength and stability of screws connection. Clean and remodify the spark plug port, simple to operate, high working efficiency. Used to quickly and efficiently repair damaged spark plug threads. Comes with a tool box, keep all the tools organized and easy to carry. Spark plug thread repair group, durable and easy to install tap, must be greased before use, otherwise it is easy to damage tap Product Description Condition: 100% Brand New Item Type: Spark Plug Thread Repair Kit Material: Carbon Steel Repair Tool Thread: M14 x 1.25 Repair Tool Thread Length: 11.2mm/0.4in, 17.5mm/0.7in Screw Tap: M16 x 1.25 Package :15 x Repair Tool /1 x Screw Tap/1 x Tool Box