The AR-STONER Castle Nut Wrench Multi Tool is an essential tool when building your next AR-15. This versatile tool is made from 4140 steel and hard coated with manganese phosphate for durability. The tool offers excellent functionality and performance at a great price point. Features4140 SteelManganese Phosphate FinishCastle Nut Wrench - (Open Style, Compatible with all styles of tubes).750" Flash Hider Wrench FlatsCompatible with A2 Buffer Tube1/2" Breaker Bar/Tension Wrench3/16" Allen (For Grips)3/8" Allen (For Scope Mounts & Other Accessories)Bottle Opener For Your Favorite Beverage