PRI G1 the original Flip Up Front Sight with .750 w/ set screws and thumb wheel elevation adjustment.  The base is solid 4140 cast steel with provision for the gas tube an integral part of the unit. Front post is constructed of T6 6061 hard coated black anodized aluminum. Front post uses a thumb wheel for elevation adjustments. Sight weighs 4.8 ounces. The center line of barrel to line of sight is 2.57".  This sight requires flats to be machined into the barrel.