Build the custom rifle you want without shooting holes in your budget. The Anderson Manufacturing EXT 10.5 Blackout Upper has a forged build featuring a 10.5 heavy barrel with 1:8 rate-of-twist rifling, Knight Stalker flash hider and .1015 gas port. Pistol-length EXT handguard. Adjustable gas block and pistol gas system. Color: Blackout. Type: AR-15 Uppers.