Guntec USA AR-15 Low Profile Gas Block w/Carbine Length Gas Tube .750 Diameter 3 Set Screws Steel. 750 Diameter Stainless Steel Three Set Screws -New Design Short Version Allen Keys Included Specifications for Guntec USA AR-15 Steel Low Profile Gas Block: Manufacturer: Guntec USA Fabric/Material: Steel Caliber: .223 Remington Gun Make: AR Platform Gun Model: AR-15 Condition: New Gas Block Journal Size-Length: 0.75 in Package Contents: Guntec USA AR-15 Steel Low Profile Gas Block What firearm models does the manufacturer say Guntec USA AR-15 Steel Low Profile Gas Block is compatible with? The manufacturer suggests that Guntec USA AR-15 Steel Low Profile Gas Block is compatible with AR-15GUNTEC USA GT750SS-CTUBE: AR-15 Steel Low Profile Gas Block.750 Diameter3 Set Screws w/Carbine Length Gas Tube