This gas block replaces your existing front sight and allows the user to mount accessories to its two picatinny rails. This gas block allows the mounting of our forearms without the removal of your muzzle accessory. Purchase our gas block mounted flip front sight (YHM-9584) to retain your iron sights. Gas port size: 0.125"
- Mounted by the use of four socket head cap screws using a 7/64" Allen wrench
- Bore diameter of .750 inches
- Made from high quality steel
- Finished with a Mil. Spec. phosphate coating.