1.Preset speed mode(high-mid-low speed)> 2. A gentle,pulsed stimulus begins to increase at a rate specifically designed for patient comfort. 3.If the patient indicates perception,simply release the button, the stimulus stops immediately, but the numbers remain frozen on the screen for about 3 minutes. 4.Specifically designed for patient comfort. 5.Convenient to operate. 6. Maximum stimulus ---80.between 0-40,the patient feels ache and anesthesia, alive teeth nerve. 7.Between 40-80,with above-mentioned reaction, part of teeth nerve dead;80,no above-mentioned reaction, dead teeth nerve. 8.The device turns itself off in three minutes after operation(No wasted batteries).