The revolutionary and patent-pending FiteLite DFX (Dual-Feed Conversion) is a compact and lightweight "drop-on" upper receiver group that readily fits all MIL-Spec AR15/M16 or M4 pattern lower receivers and delivers reliable, belt-feed performance at your fingertips! In addition to feeding from M27 linked ammunition, the innovative DFX retains the ability to seamlessly transition to standard box type AR15/M16 magazines at user discretion, hence its patented Dual-Feed capability.Features :Gas-Piston OperationHeavy Duty, Free-Floating Fixed Barrel SystemFree-Floating Slimline Picatinny Rail HandguardNo Permanent Modification Required to the Lower ReceiverIncludes (100)-M27 Links