Spike's Tactical Complete Upper Receiver, 223 Rem/556NATO, 16" FN Hammer Forged Barrel, 1:7 Twist, Fits AR Rifles, Mid-length Gas System, Front Sight Post, Black Finish STU5435-MLS
Specifications:

Type	Complete Gas Impingement
Caliber	223 Remington/5.56 NATO
Sights	A2 Front
Barrel Length	16"
Barrel Material
Twist	1:7"
Barrel Description	Cold Hammer Forged
Barrel Finish	Black
Receiver Description
Receiver Finish	Black
Handguards	Mid Length
Handguard Finish	Black
Barrel Length Range	16.00" to 17.99"