Features: This product is .83HZ low frequency generator, features high accuracy and stability. High stable frequency acquisition : high stability pulse chip, precision correction capacitance, precision multi-loop adjustable resistor. High quality polymer batteries, with overcharged, over voltage, overcurrent protection. There is no voltage ripple in the voltage supply. With work toggle switch, easy to use. wave can be applied to HIFI or sleep. Specification: Power: 12V 1A android charging cable Polymer battery capacity: 2300mah Working time: 200 (full of electricity) Size:132x108x30mm Weight: 200g wave applied to sleep: 1. It is recommended to buy a trial, on a bedside, more than 1 meter from the human body distance. 2. The trial, plus the appropriate weight for anti-vibration treatment. 3. The appropriate use of paper cloth cloth block indicator light, remove the product at night light 4.Try it for a week and analyze seven of experience. Material: Plastic+metal colour: As shown Package Contents: 1 x Ultra-low frequency pulse generator 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 a little different from the real thing. The measurement allowed error is +/- 1-3cm.