AR-15/M16 Flattop Upper Receiver
This video showcases the AR-15/M16 Flattop Upper Receiver by D.S. Arms.
WARNING: Never attempt to disassemble or reassemble a firearm unless you are absolutely certain that it is empty and unloaded. Visually inspect the chamber, the magazine and firing mechanism to be absolutely certain that no ammunition remains in the firearm. Disassembly and reassembly should follow the manufacturer’s instructions.