Well R-2 Scorpion AEP (Automatic Electric Pistol).
Based on the Tokyo Marui Vz.61 Scorpion AEP, the Well R2 clone is a faithful representation of the classic '60's era Cold War Machine Pistol produced by Czechoslovakia.
This AEP in stock form fires 0.2g BBs at a speed of around 225 FPS and an ROF of about 8 RPS on the stock 7.2v NiMH battery pack.
The adjustable Hop Up allows the user to dial in their shots for a specific weight/type of BB. I have found the maximum accurate effective range to be between 70-90'
The R2 Scorpion features the exact same AEP gearbox as the MP7 AEP, so any gearbox upgrades for the MP7 will work on this gun.
The Well R2 comes stock with a 60 round stick magazine, a 300 round drum magazine, a special 7.2v NiMH battery pack, and a special charging cradle for the battery.
Upgrades, while available, are not cheap and upgraded performance is pretty much limited to around 300 FPS with 0.2g BBs, which is perfect for CQB.
My Scorpions have been upgraded with SHS AEP gears, 7.4V "Gum Stick" LiPo batteries, and a custom non-AB MOSFET (to preserve the unique trigger contacts).