If you are familiar with the Colt 6920, you will know these are the most in-spec semiautomatic M4A1 Carbines available on the Civilian Market. Colt 6920's are Colt's M4A1 Carbine marketed for the Law-Enforcement community with 16.1" threaded 1/7 M4-profile barrels and allocate the installation of the M203 Grenade Launcher. Each Colt 6920 has correct M4 feed-ramps on both barrel and upper-receiver. The upper-receivers are in M4A1 flat-top configuration with correct t-marks and detachable carrying-handles. Lower-receivers are reinforced lower-receivers with small-pin firing control groups, staked four-position mil-spec receiver extensions with heavy buffers and M4A1 telestocks. Previously, ALL Colt 6920's used over-sized .170" pins in their firing control groups. These Colt 6920's all have correct .154" pins in their firing control groups and allocate the installation of other firing control groups. Each Colt 6920 includes two 20 round magazines, manual, cleaning kit, and sling. $1300 + FFL transfer or CPL. Thanx. SAMMY!