Prowin AR9 Conversion Kit for Marui M4 MWS GBB CS600 If it isn't internal

If it isn't internal

x1 GHK 553 Tactical GBBR

Designed exclusively for Vertx

SKU GP710O Item Weight (gram) 500 Major Color Olive Drab Manufacturer G&P Hop-up N/A Shooting Mode N/A Gearbox Type N/A Fit Battery Pack N/A Bullet Type N/A Pistol Power Source N/A

This AK104PMC-E is an example of that

Prowin AR9 Conversion Kit for Marui M4 MWS GBB CS600 If it isn't internalProwin AR9 Conversion Kit for Marui M4 MWS GBB Includes: CNC Aluminium AR9 Conversion kit x 1 New version 47rds Lightweight Glock long magazines ( Marui system ) x 3 Reinforced Loading Nozzle x 2 Conversion kit only, Marui MWS Rifle not Included **Modification on upper receiver , bolt carrier and bolt catch is needed in order to install this conversation kit, please check the installation manual for details.**