DRD Tactical Aptus Takedown AR-15 Rifle has a patented internal recoil system takes the place of the standard buffer and recoil spring found on traditional ARs. This allows the stock to fold for storage or use in tight spaces. A non-reciprocating left side charging handle brings the rifle to locked and loaded status in an instant. The upper and lower receivers are machined from billet aircraft aluminum for a precise fit. The 16" 5.56 NATO barrel has a 1:7 twist and 1/2"-28 TPI, A2 flash hider. The barrel indexes and attaches to the receiver with a large barrel nut. No tools are needed. Simply line up the gas tube, insert the barrel and hand tighten the barrel nut. Slide the free floating rail over the barrel and attach it to the barrel nut, push the cross pin and engage the tightening lever. Your Aptus is assembled in 60 seconds or less. - CALIBER 5.56 NATO (accepts .223 Rem) - MAGAZINE (1) with 30rd capacity - BARREL 16" Barrel Nitride Finish, 1:7 Twist, 1/2"-28 Threaded Barrel with A2 Flash Hider - RECEIVERS Billet Aircraft Aluminum Upper and Lower Receiver, Black Hard Coat Type III Anodized Finish - STOCK Magpul Folding Butt Stock