This is a Armalite AR known as the M-15 Light Tactical Carbine chambered in 223 Remington, model M15LTC16.
The M-15(TM) Light Tactical Carbine (LTC) provides shooters with a versatile" hard-hitting modern sporting rifle in a streamlined and affordable package. With features such as Armalite's own free-floating tactical Key-Mod handguard and low-profile gas block" the Light Tactical Carbine carries a modern profile in a light and scalable package.
Features:
KeyMod Handguard
Low-Profile Gas Block
Lightweight
6-Position Collapsible Stock