● External HOP-UP quick adjustment design to adjusting without disassembly. ● One-piece upper receiver assembly, four-sided MIL-STD-1913 rail section at the forend. ● Folding front sight and rear sight. and the charging handle can be interchanged left and right, ● buttstock can be side-folded and retractable. ● The new version of the bolt carrier group, heavy alloy carrier, nylon feed nozzle, adjustable.