The Knights Armament Company URX 4 for AR-15s in 5.56mm is a free floating continuous top-rail handguard system that utilizes the M-LOK mounting brackets developed by Magpul. The modular M-LOK system allows the shooter to customize the location of accessories such as lasers, lights and grips.
- URX 4 13" rail M-LOK
- Knight's Integrated Barrel Nut (IBN)
- Shim set and wrench