All / Magazine All Upper Receiver Lower Receiver Stocks and Braces Triggers Grip Safety Accessories Charging Handle Bolt Carrier Groups Ejection Port Cover Barrels Gas Blocks Muzzle Devices Silencers and More Handguards Magazine Get Your Lower Receiver Here! Aero Precision M4E1 Lower Receiver- Black Aero Precision M4E1 Lower Receiver- FDE Anderson Lower Receiver- Black