Dremel,10.8 Lithium Ion Battery, 50% More Power & 40% More Speed, Holds A Charge 6 Times Longer Than Standard Nicad Batteries, Can Be Recharged At Any Time Without Damaging The Original Run Time Or Capacity, For The 400 XPR Rotary Tool

10.8 volts of power for light duty precision
For use with models 8000-01 and 8001-01