The BlueSpot 10 Pce Bolt Remover Set is manufactured from heat treated chrome molybdenum steel for increased durability. Designed for the safe removal of locking wheel nuts, bolts, and studs. Suitable for hand and power tools. Can be used with 3/8" breaker bar/ratchet. Complete with handy carrying case for quick and easy storage. Sizes 9, 10, 11, 12, 13, 14, 15, 16, 17 & 19mm. For manufacturers lifetime guarantee you just need to register online within 30 days of purchase.