This is a Armalite known as the M15 chambered in 223 Remington, model M153GN18.
Purpose built for 3-Gun and practical rifle competition" the M153GN18 is ready to dominate" right out-of-the-box. A Timney 4-lb." single-stage trigger and Ergo wide grip come standard. The light weight MBA-1 buttstock features an adjustable cheek piece and length-of-pull.
Features:
Adjustable Gas-Block
MBA-1 Buttstock
Timney Trigger
Tunable Muzzle Brake