Tiger Rock GTPB GB01-B Assembled .750 Low Profile Micro Gas Block and Sliver Pistol Length Gas Tube Black Small. Designed with the minimum profile to fit under nearly any quad rail system it snugly fits standard .750 diameter barrels. Specifications for Tiger Rock Assembled .750 Low Profile Micro Gas Block and Sliver Pistol Length Gas Tube: Manufacturer: Tiger Rock Color: Black Gas Block Journal Size-Diameter: .750 in Gas System Length: Pistol Length Gun Make: AR Platform Gun Model: AR-15 Package Contents: Tiger Rock Assembled .750 Low Profile Micro Gas Block and Sliver Pistol Length Gas Tube Roll Pin 2 Set Screws Allen Wrench What firearm models does the manufacturer say Tiger Rock Assembled .750 Low Profile Micro Gas Block and Sliver Pistol Length Gas Tube is compatible with? The manufacturer suggests that Tiger Rock Assembled .750 Low Profile Micro Gas Block and Sliver Pistol Length Gas Tube is compatible with AR-15Tiger Rock GTPBGB#: GTPB GB01-B Assembled .750 Low Profile Micro Gas Block and Sliver Pistol Length Gas Tube Black Small