Compatible Tools: For use withDremel cordless rotary tools 8240, 8250 & 8260, and all Dremel Blueprint tools CS12V-S1C, CS12V-S1, DD12V-S1, MM12V-S1 Maximum Power Output: 12V Max power to handle all relevant applications Extended Runtime Capacity: 2AH (amp-hour) capacity for longer runtimes Convenient Spare Battery: Spare battery pack so you don't have to quit working to recharge your battery Compatibility Notice: Not compatible with Dremel 8220