Features The 7.83Hz Schumann wave generator with very low frequency features high accuracy and stability with MSDS certification. The high-stability frequency acquisition parts include a high-stability pulse chip, accuracy correction capacitance, and a multi-loop adjustable resistor. High-quality polymer batteries are equipped with overcharge, overvoltage and overcurrent protection. There are hardly any voltage ripples in the mains. With work switch, easy to use. Schumann waves can be applied to HIFI or sleep. Rechargeable model, small and portable, equipped with a 20 cm charging cable. Newly optimized circuit designs and gold-plated actuation circuit. Function: 1. The Schumann wave itself does not work directly on sound or video products to improve sound quality, but the role of the space environment to relax the human body and mind, improve the human body's perception of sound and image, improve human health, improve work efficiency and mental stress , also bringing better results. 2. Used in audiovisual space, bedroom, office, innovation space, tea ceremony, truth realization space. Specification: Item Type: Ultra Low Frequency Pulse Generator Size: Approx. 68 x 52 x 12mm/2.7 x 2 x 0.5 inch (Length x Width x Height) Power supply: 5V micro-USB charging cable for Android interface Battery: 1200mAh lithium polymer battery Use time: Charging current: 250mA Full charge time: approximately 6 hours Working current: 7MA Full charge Used for: approximately 200 hours (168 hours per week) Charging cable: approx. 20 cm/7.9 in Package List: 1 x Ultra Low Frequency Pulse Generator 1 x USB Cable 1 x Screwdriver Note: 1. Original imported core electronic components. It is recommended to use multiple units in a dispersed manner, the effect will be more felt.2. Do not tear off the protective film, do not disassemble and do not touch individual components one at a time when the product is being tested. High stable frequency is strictly regulated and tested by the factory.3. Please note that the new and old type of this product will be sent randomly, and make sure you don't mind before ordering. Package List 1 x Ultra‑Low Frequency Pulse Generator 1 x USB Cable 1 x Screwdriver