SOCOM MFG receiver (one heavy duty mother!!!), ZM weapons 16" upper (reconfigured to be able to fire without the buffer tube and spring normally found in the AR15 style rifles. Check out ZM weapons website for additional information), upgraded side folding, collapsable stock, IOR scope, heavy duty rings, rail covers, dura coated lower receiver and SPR grip. Email for additional photos if interested. Also looking at interesting trades. Anything HK related will be considered.