DoubleStar Adjustable Gas Block Picatinny .750in Black. .750". Machined from 6061 T6 aluminum. Stainless Adjustment Screw with brass locking screw to prevent damage to the threads. Self tapping set screws on bottom for perfect seal and fit to barrel. Perfect for target shooters or those using suppressors. Specifications for DoubleStar Adjustable .750in Gas Block Picatinny: Manufacturer: DoubleStar Color: Black Fabric/Material: 7075-T6 Aluminum Gas Block Journal Size-Diameter: .750 in Size: One Size Gun Make: AR Platform Gun Model: AR-15 Condition: New Features of Doublestar Adjustable Gas Block Picatinny .750in Adjustable Gas Block Picatinny Rail. Size: .750" Finish: Hard core anodized Package Contents: DoubleStar Adjustable .750in Gas Block Picatinny What firearm models does the manufacturer say DoubleStar Adjustable .750in Gas Block Picatinny is compatible with? The manufacturer says that DoubleStar Adjustable .750in Gas Block Picatinny is compatible with AR-15DoubleStar DSC765: Adjustable Gas Block Picatinny .750in Black