Manufactured from high quality chromium nickel stainless steel, V-Coil inserts provide high strength internal threads that resist the effects of temperature and corrosion. Their unique design ensures superior threads whose compound performance cannot be reproduced by any other single fastening thread insert and because of their compact size they can be incorporated info existing designs where no previous provision has been made. On kits upto and including 1/2" they include tap, drill, insert tool and tang break tool and 1.5 D V-Coil thread inserts. On kits after 1/2" they include the tap, insert tool and 1.5 D V-Coil thread inserts 3/16", 1/4" & 5/16" Kits include 20 inserts 3/8" Kit includes 15 inserts 7/16", 1/2", 9/16" & 5/8" Kits include 10 inserts 3/4" & 7/8" Kits include 5 inserts 1" Kit includes 4 inserts All V-Coil thread inserts are compatable with Helicoil