The Colt LE6920 Monolithic Upper Receiver Conversion Kit is a complete centerfire upper assembly chambered in 5.56mm NATO, built around Colt's standard-issue law enforcement pattern carbine. This factory kit provides an immediate, plug-and-play solution to convert any standard AR-15 lower receiver group into a duty-grade Colt platform. It features a 16.1-inch chrome-lined carbon steel barrel equipped with a 1:7" right-hand twist rate, a direct gas impingement operating system, a mil-spec fixed A2 front sight tower, and a dual-layer polymer drop-in handguard.