This ultra-low frequency Schumann wave generator can be used at home to reduce metal pressure, and it also has a good effect on insomnia. If you have insomnia, you can try this product, it will not disappoint you. Characteristics:A Schumann resonance (SR) is a set of spectral peaks at an extremely low frequency (ELF) portion of the spectrum of the earth's electronic magnetic field. This Schumann wave generator has high precision and good stability, giving you a better experience. Need to connect type-c wired power, no battery needed, easy to use. You can use it at home to reduce insomnia or in the office to increase productivity. It has a wide range of applications. The operation is simple and can be used directly after connecting the power supply. Both beginners and amateurs can get started quickly. Specification: Material: Plastic Dial Diameter: 82mm / 3.2in Power Supply: Type-c Port Resonance Frequency: 7.8Hz (Adjustable) Package Size: 100 * 82 * 20mm / 3.9 * 3.2 * in Package Weight: 18g / 0.6ounce Packing List: 1 * Schumann Resonance Generator