E-Z Coil Thread Repair Kit for Metal - Economy - 1-8 x 1DEverything needed to repair or reinforce tapped holes in metal in a convenient, easy-to-order kit.FeaturesEconomy kits include threaded inserts, STI tap, and installation tool.Kit Contains: (3x) 21710, (1x) M1023, (1x) 21770Applications:Soft metals: aluminum, cast iron, magnesium, etc.