Features This product is Schumann wave 7.83HZ very low frequency generator, features high accuracy and stability. High stable frequency acquisition elements: high stability pulse chip, accurate correction capacitance, accurate multi‑loop adjustable resistor. High quality polymer batteries, with overcharged, overvoltage, overcurrent protection. There is almost no voltage ripple in the voltage supply. With work toggle switch, easy to use.Schumann wave can be applied to HIFI or sleep. We are committed to bringing the best shopping experience to customers and will solve your problems in time. Specifications: Model: CF-FM783-BA Power: 3.7V for android charging cable Polymer battery capacity: 1200mah Time: charging current 250mA, 6 hours full of electricity Working current: 7mA Working time: 200 hours(full of electricity) Size: Approx. 7 x 5.5 x1cm/2.76 x 2.17 x 0.39inch Weight: 83g Schumann wave applied to HIFI: 1. The player has a certain HIFI experience, HIFI equipment level can not be too low. 2. Can hear, the difference between the same system on the different wire to bring the tone changes. 3. It is recommended to buy two sets of trial (the effect is better). 4. when the product will be placed on the speaker, plus the appropriate weight for anti-vibration treatment. Schumann wave applied to sleep: 1. It is recommended to buy a set of trial, on a bedside, more than 1 meter away 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 days of experience. Package Included: 1 x Ultra-low frequency pulse generator 1 x USB cable 1 x Screwdriver Note: 1. Package included a generator, power supply are not included. 2.This item is finished product, not need to assemble. 3. Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering. Package List