DPMS Low Profile AR-15 .750in Gas Block Black. 750 diameter. Low profile steel construction with 2 set screws and fits under most railed hanguards. Specifications for DPMS Low Profile AR-15 Gas Block: Manufacturer: DPMS Color: Black Gas Block Journal Size-Diameter: .750 in Gun Make: AR Platform Gun Model: AR-15 Package Contents: DPMS Low Profile AR-15 Gas Block What firearm models does the manufacturer say DPMS Low Profile AR-15 Gas Block is compatible with? The manufacturer suggests that DPMS Low Profile AR-15 Gas Block is compatible with AR-15DPMS DP51655151900: Low Profile AR-15 .750in Gas Block Black