Selling a very, very rare PSG-1 gearbox with 100% Systema upgrades and a custom BTC MKII Chimera mod. You can’t kind these parts anymore. They are extremely robust (can handle over 600fps) and extinct everywhere in the world. This is really a once in a lifetime opportunity. I have some PSG and G3 externals as well (see my PSG-3 listing). Internals of the gearbox include: Gearbox * Upper Half * Systema Air Nozzle with Internal O-Ring * Systema Aluminum Cylinder Head with Duel O-Rings * Systema Bore-up non-ported Cylinder * Systema Piston Head with Ball Bearings * Systema Aluminum Piston (AOE corrected) * Systema 160% Spring (PSG-1 Type) * Lower Half * Systema Gearset * Systema 6mm Oil Tempered Bushings * Custom Trigger Unit with Panasonic Detection Switches for Trigger and Pre-cocking Lever * Prometheus Shim Set * Custom CNC ARL * Systema High Torque Motor Electrical * Chimera MKII MOSFET * 16AWG Low Resistance Wiring with Deans Connector * Custom wire harness for PSG-1 I also have some extra springs and other parts that will be included. If you have any questions feel free to ask. If you want to upgrade your PSG-1, this is the all in one package. Thanks for looking and have a great day.