The Knight's Armament Free Float Rifle RAS (KAC PN: 21318) is KAC's free-float Rifle-length Rail Adapter System for AR-15/M16 pattern rifles. The KAC RAS (Rail Adapter System) provides full-length MIL-STD-1913 Picatinny rail coverage on all four sides of the handguard, enabling mounting of lights, lasers, grips, and other Picatinny accessories at any position. The free-float design attaches directly to the barrel extension/upper receiver and does not contact the barrel, allowing the barrel to vibrate freely for improved accuracy. The RAS was a pioneering accessory rail system that set the standard for modern tactical handguards.
- Part Number: 21318
- Type: Free-float rifle-length quad rail (RAS)
- Compatible Platforms: AR-15 / M16 pattern rifles with standard barrel extension (rifle-length)
- Rail System: MIL-STD-1913 Picatinny on all four sides
- Material: Aircraft-grade aluminum
- Manufacturer: Knight's Armament Company (KAC), Titusville, Florida, USA
