The 3 hole Rail Riser mount was originally designed to set on the M4 flattop receiver but it has proved to be a versatile base for many different purposes. The aluminum rail lifts the mounting surface up .450" and allows the extension to the front or rear
PRI AR15 M16 Flattop Riser 3 Hole
PRi AR15 / M16 Flattop Riser 3 Hole. Rail riser is constructed of T6 6061 hard coated black anodized aluminum. The full 1913 rail is elevated .45" with an overall length of 6.375" with 1.375" of overhang. The riser weighs 4.3 ounces.