This is a highly upgraded ARP-9. These are the upgrades. 1. V2 Retro Arms gearbox 2. Red dress up kit 3. Gate Aster 4. Gate quantum trigger 5. Maxx ME pro hop up 6. Prometheus barrel 7. Battery extension 8. Custom motor 9. SHS 12:1 gear 10. Nintendo dress up kit 11. ARP-9 drum mag 12. Clone red dot 13. Metal teeth piston( I can't remember the brand) 14. Cylinder set is also upgraded but I can't remember the brand. This is a really cool looking gun with performance to match it. It was firing at 1.12j( Our indoor field requirement) @ 35 to 45 rof. I would prefer a meet up so you can try the gun as this is a no return sale. I am trying to get $500 for it. The next best thing you can do with this aeg is to add a Siegetek DSG or HPA it. Text me at (801)425-9854 for faster transaction.