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 , overcurrent protection. There is no ripple in the 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.