This Yankee Hill Machine YHM-9386A Single Picatinny Rail 0.625 Inch Gas Block replaces your existing front sight and allows the use of dovetail mounted accessories. Installs easily with two cap screws onto barrels with a diameter of .625 diameter under the front sight. Purchase our dovetail mounted flip front sight (YHM-9584) to retain your iron sights.
Made from high quality steel and finished with a Mil. Spec. phosphate coating. Made in the U.S.A