Shop name:Chong Qing Shuo Yue Ke Ji You Xian Gong Si The 7.83HZ Schumann Wave Ultra-Low Frequency Pulse Generator is of high accurancy and stability. The pulse generator is adopted with high stable frequency acquisition elements, precision correction capacitance, precision multi-loop adjustable resistor, display solid capacitance. Equipped with high-quality lithium polymer battery, with overcharged, over-voltage, over-current protection. There is almost no voltage ripple in the voltage supply. You can apply it in your bedroom, office, study, tea room and so on. Easy to operate, with a USB cable and a screwdriver for easy installation. Battery: Lithium polymer battery Battery capacity: 850mah Time: charging current 250mA, 6 hours full of electricity Working current: 7mV Working time: 200 hours(full of electricity) Power: 5V -usb android charging cable Colour:As Shown Material:PC+metal Package Contents: 1 x Ultra-low Frequency Pulse Generator 1 x USB Cable 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.