Matador Arms MAT-9K AR-9 9mm 5in Roller Delayed Upper Receiver

Matador Arms MAT-9K AR-9 9mm 5in Roller Delayed Upper Receiver\n\n- Roller Delayed buffer-less, side charging, non-reciprocating upper with patent-pending EZTS Easy Take-down System\n- Slim profile for maximum weight reduction and compatibility with AR-9 lowers; works with Glock, Sig Sauer, Colt Stick Magazines, HK MP5, CZ Evo Scorpion type magazines\n- When used with an AR-15 lower, Mag-X magazine conversion kit or Endomag may be required\n- Roller Delayed system reduces recoil; no buffer tubes required; flexible charging handle\n- Construction: 6061-T6 Aluminum with anodized finish; 5in 4150 CMV steel barrel; 1:10 twist; 1/2x28 threads; Thread Protector muzzle device\n- Handguard: 13 in length, M-LOK rails on both sides and bottom\n- Compatible with LRBHO lower receivers\n- NATO 1913 top rail; Made for AR Platform AR-9\n\nSpecifications: Caliber 9mm Luger; Barrel Length 5 in; Barrel Profile Tactical Lightweight; Twist Rate 1-10; Threads 1/2x28; Muzzle Device Thread Protector; Finish Anodized; Fabric/Material 6061-T6 Aluminum; Handguard Length 13 in; Gun Rail M-LOK; Gun Make AR Platform; Gun Model AR-9; Barrel Material 4150 CMV Steel