Frequently bought together:
Description
Heckler & Koch–pattern free-float quad rail for HK416, HK416A5, M27, MR223 and MR556 rifles. Approximately 9.5" overall. Four-sided MIL-STD-1913 Picatinny rail at 12, 3, 6, and 9 o’clock.
Side window is the gas-regulator cutout for adjustable (N/S) gas blocks. Rear hole accepts the factory HK handguard lock screw. Mounts to the HK 416-style barrel nut.
Fits: HK416 / 416D / 416A5, MR223, MR556 / MR556A1, and in-spec 416 clones using the HK barrel nut. Common with 10.4", 14.5", and 16" barrels.
Does not fit: Standard AR-15 delta-ring uppers, HK417 / MR762 rails, or aftermarket systems that need their own nut (Geissele SMR, Strike GRIDLOK, etc.) unless those parts are already on the rifle.