UAG-CQRC Aluminum Carbine-Length Handguard Quad-Rail System w/ Covers UAG UAG-CQRC Aluminum Carbine Length Weaver / Picatinny Quad Rail Handguard System from the The Global Sportsman. Comes with two alloy handguard halves, Allen head screws, and twelve rail rubber covers. This is a carbine-length AR-15/M-4 quad-rail system, so it will be too short for full-length AR-15/M-16 …