1. Professional Electrostatic Tester: non-contact electrostatic qualitative testing gauge for quickly detecting the static of the object. 2. Mini Palm Size: easy to operate by single hand, convenient to carry around. 3. Three Indicator Light: green for power, red for positive charge and blue for negative charge. 4. Power Supply: powered by 2 x CR2030 battery, low power consumption. 5. Wide Applications: it is widely used in the measurement of static electricity on the of masks, non-woven fabrics, plastics, films, rubber, fiber composite plates and other products. Product Name:Static Tester Model No:JED100 Power supply:2 x 3V CR2030 batteries Product size: 80mmx60mmx25mm Working temperature: 0-50 Sensing range: 100V-20KV Measuring method: Handheld non-contact Measuring distance: 10mm(best) Response time: 1S-3S How to use: 1. Turn on the power by toggling the switch upward 2. the positive and negative charge zero button for operation 3. Move the test back and forth close to the of the object to be measured (about 10mm) 4. Light up the red light for positive charge, light up the blue light for negative charge. Red light and blue light does not light up that does not have static electricity or with a weak static electricity Color:Black Material:ABS Package Contents: 1 * Electrostatic Detector Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.