TROY Industries A3 Complete Upper, 223 Remington/556NATO, 16 Barrel, A2 Flash Hider, Free Float M-LOK Handguard, Andodized Finish, Includes Bolt Carrier Group SUPG-A3M-16BT-00 Troy Industries AR-15 A3 Upper Receivers are lightweight and ultra-low profile. Developed specifically for today's war fighter and Law Enforcement led by Special Operations field requirements. The M-Lok Battlerail handguard is machined from hardened aircraft aluminum with stainless steel components and finished in MIL-SPEC hardcoat anodizing" the M-LOK rails are light and sleek. The M-LOK slots make for mounting your favorite M-LOK accessories quick and easy.