Precision Reflex Low Profile Gas Block SASS/DPMS .308 .936 Diamter Black. The gas block is held into place with (3) #10-32 screws. The overall length is 1.25in height 1.54in and width 1.1in with a .936 ID. Height from bore center line to the top of the gas block is .87in for clearance. Specifications for Precision Reflex SASS/DPMS .308 Low Profile Gas Block: Manufacturer: Precision Reflex Color: Black Fabric/Material: Aluminum Gas Block Journal Size-Diameter: .936 in Caliber: .308 Winchester Gun Make: AR Platform Features of Precision Reflex SASS/DPMS Low Profile .936 Gas Block: The gas block is constructed of high strength steel and a black Nitrite finish The gas block is held into place with (3) #10-32 screws The overall length is 1.25" height 1.54" and width 1.1" with a .936 ID Height from bore center line to the top of the gas block is .87" for clearance. Package Contents: Precision Reflex SASS/DPMS .308 Low Profile Gas Block Precision Reflex 03-SASS-01: Low Profile Gas Block SASS/DPMS .308 .936 Diamter Black