Feature: 1. Preset speed mode (high-mid-low speed). A gentle, pulsed stimulus begins to increase at a rate 2. Specifically designed for patient comfort. If the patient indicates perception, simply release the button. The stimulus stops immediately, but the numbers remain frozen on the face for about 3 minutes. 3. Convenient to operate Maximum stimulus--80. Between 0-40, the patient feels ache and anesthesia, alive teeth nerve. Between 40-80,with above-mentioned reaction,part of teeth nerve dead 80, no above-mentioned reaction, dead teeth nerve. 4. The device turns itself off three minutes later after operationed (No wasted battery) 5. Battery-operated, Standard 9-Volt battery, Extremely economical 6. One year quality guaranteed Specifications: 1. Output: DC 9V 2. Current: 50mA 3．Voltage range: DC 6.0-10.0V 4．Size: 186*38*24mm 5．Net Weight: 220g