DoubleStar Race Gun Gas Block .750in Black. .750"Designed to reduce the weight of the gas block while retaining the original mounting area giving the best possible seal for competition shooters. 1045 steel with parkerized finish. Specifications for DoubleStar .750in Race Gun Gas Block: Manufacturer: DoubleStar Color: Black Fabric/Material: 1045 Steel Gas Block Journal Size-Diameter: .750 in Size: One Size Gun Make: AR Platform Gun Model: AR-15 Features of Doublestar Race Gun Gas Block .750in DSC Race Gun Gas Block Size: .750" Finish: parkerized Package Contents: DoubleStar .750in Race Gun Gas Block What firearm models does the manufacturer say DoubleStar .750in Race Gun Gas Block is compatible with? The manufacturer says that DoubleStar .750in Race Gun Gas Block is compatible with AR-15DoubleStar DSC761: Race Gun Gas Block .750in Black