Features: ●Build withStable GHK M4 Ver.2 GBB system. ●2020 revision of the Colt authorized marking and improve surface finish. ●G-Style MK16 SMR 13.5" handguard, CNC process aluminum alloy, anodized surface finish, with marking. ●G-Style ACH type charging handle, CNC process aluminum alloy, anodized surface finish, full marking. ●SF-Style SOCOM type STEEL 4-prong STEEL flash hider. ●DD-Style GOV Mid-Length type 14.5 STEEL outer barrel. ●G-Style STEEL gas block, with corresponding gas tube. ●Comes with KAC type rare flip-up sight, and LMT Gen2 type retractable stock. ● New HOP-UP adjustment system and 6.03mm precision inner barrel. ● New CNC process Steel Bolt Carrier, much durable and worked smooth. ● Reinforce nylon feed nozzle, steel parts of fire control, 6th version hammer. ● New version of the magnetically bolt catch system, reliable lock of the bolt carrier group. ● Aluminum die-casting receiver, treatment of anodized processing, not easy to scratch rust. ● Buffer extension thread of the lower receiver is stronger, less broken. ● New GMAG type M4 gas magazine, same effective but super light-weight. ●Compatible with ALL gen. GHK M4 / G5 / GMAG gas magazine.