5.25 long Picatinny/ MIL-STD 1913 rail adapter mount for M16/ AR15/ M4 receivers with A1 & A2 carrying handles.Picatinny rail adapter for AR15 carry handles, designed for mounting optics and accessories to the top of the carry handle.Compatible with A1 and A2 receivers with the carry handles, also works with most mil-spec detachable carry handles.See-through channel allows the use of the iron sights when mounted into carry handle.Includes mounting thumb nut.Constructed of black anodized aluminum