Aluminum .875″ gas block with top picatinny rail. This gas block has the gas port off set .025″ rearward. This allows the gas port in the block to line up with the port in the barrel when a hand guard end cap is installed. The end cap is typically used to retain the front end of standard GI plastic hand guards. The rail on the top of the block is at gas block height, NOT same-plane with the receiver.
This .875″ diameter gas block is designed to work on modern/short 1.1″ long gas block journals (Tromix Barrel). It will not work on old-school barrels with long 1.95″ gas block journals. The barrel must also be no larger than .850″ diameter from the front edge of the gas block journal to the muzzle.
If you’re not using a Tromix barrel, be sure to measure the length of your barrel’s gas block journal and barrel diameter before ordering.