The RADIUS Drop-in carbine handguard rail system offers shooters an easy upgrade over polymer handguards. Milspec materials and finishing combined with an improved patent-pending clamping system ensure reliable performance and durability with unmatched ease of installation. Four Quick-Detach swivel bushings with anti-rotation stops allow rapid installation and removal of popular QD Swivel-equipped slings. All rails are laser-numbered for repeatable accessory installation. This excellent rail system is proudly made in the USA by a DOD-contract holder in current production on the M4 and M5 rail systems used by all branches of the US military. The RAIDUS drop-in rail system is made from the same material, on the same machines, and by the same operators as the rail systems in use by US forces around the globe.