Function: 1 Screw Repair Tool: Professional spark plug screw repair tool including 10pcs M12x1.25 screw inserts and M14x1.25 screw taps. 2. STANDARD SIZE: These repair tools have a standard screw size and are suitable for repairing spark plugs of 14mmx1.25mm. 3 STAINLESS STEEL INSERTS: These screw thread inserts are made of stainless steel and are galvanized for corrosion resistance and durability. 4 High Speed Steel Tap: Threaded tap is made of high speed steel with high hardness and high temperature resistance. 5 Applicable machines: efficient and labor-saving, especially suitable for gasoline engines, generators, diesel engines and other machines. Specifications: