Schumann wave works on the space environment, helping people relax physically and mentally, improving the body's perception of sound and images, and may contribute to better work efficiency and stress relief. This is a 7.83Hz ultra-low frequency Schumann wave generator with high accuracy and stability. It uses high stability pulse chips, precision correction capacitors, and precision multi-loop adjustable resistors. Equipped with a polymer battery with overcharge, overvoltage, and overcurrent protection. The voltage supply has almost no ripple. Features a work toggle switch for easy use. Specifications: Model: CF-FM783-BA; Power: 5V android charging cable; Polymer battery capacity: 1400mAh; Charging time: 6 hours with 250mA charging current; Working current: 1mV; Working time: 200 hours when fully charged; Size: 7 x 5.5 x 1cm/2.76 x 2.17 x 0.39inch; Weight: 83g; Color: As shown in the picture. Application for HIFI: 1. Suitable for players with certain HIFI experience; HIFI equipment level should not be too low. 2. May help perceive tone changes from different wires in the same system. 3. It is recommended to try two sets for better effect. 4. Place on the speaker with appropriate weight for anti-vibration treatment. Application for sleep: 1. Recommended to try one set, placed on the bedside, over 1 meter away from the human body. 2. Apply appropriate weight for anti-vibration treatment. 3. Use paper or cloth to block the indicator light to remove night light. 4. Try for a week and analyze the experience. Package Included: 1 x Ultra-low frequency pulse generator, 1 x USB cable, 1 x screwdriver. Note: Power supply is not included. This is a finished product, no assembly required.