New in box: Colt M4 Carbine 
Caliber  : 5.56 NATO 
Barrel length  : 16.1"
Finish  : Matte black 
Stock : 6Position stock
Sights  : MAGPUL MBUS + Sig Sauer Romeo red dot 
Weight  : 5.95 lbs 
Action  : Semi-auto 
Hand : Right 
Overall length  : 35.5"
Twist : 1:7
Type : Center fire 

This is a direct gas impingement semiautomatic rifle , threaded  1/2 × 28 TPI , BIRDCAGE A2 STYLE FLASH HIDER  , Forged 7075 T6 Aluminum upper/lower Recievers , flat top upper receiver , M4 Feed ramps  , Reversible selector switch  , Carbine length gas system  , polymer hand guard  , A2 Front sight , A2 Pistol Grip  , Magpul flip up rear and a forward assist  , foward hand stop , M lock 9" bipod , pro mag Quad rail handgard , 3 position Collapsible stock