Springfield Armory's Hellion answers the call for superior ballistic performance in a short, adaptable platform. Featuring a bullpup configuration where the action is located behind the trigger. The Hellion bullpup features a two-position adjustable gas block with suppressed and normal modes; ambidextrous controls that work in concert with a reversible case ejection system; Picatinny top rail; flip-up iron sights. These spring-loaded sights quickly pop into position, locking solidly until released. It accepts standard AR-15 pattern grips. The polymer handguard features 9 M-Lok slots for mounting accessories. Includes soft case and two exterior magazine pouches for standard pattern AR-15 magazines. Oal 28.25"- 29.75" Hand Ambidextrous Twist 1:7" Action semi-auto Muzzle 4-Prong Flash Hider Safety Ambidextrous Safety Lever Series Bullpup Sights Flip Up Front & Rear Weight 8 lbs Caliber 5.56x45mm NATO Capacity 10+1 Weight Range 8 lbs to 8.99 lbs Barrel Length 16" Receiver Material Polymer Stock Description Adj w/Cheek Riser Barrel Description Steel Metal Finish Group Green Stock Finish Group Green Barrel Length Range 16" to 16.99"