Comfotable:Lightweight and easy to use, integral safety-lock throttle lever prevents accidental start-up Great for high speed grinding, port smoothing, general polishing, and deburring Self-locking throttle lever prevents accidental starting of motor Rear exhaust air flow system that directs air away from work surface Full set: one 1/4 mini die grinder, one 1/4'' collect, two wrenches, one oil bottle