Features: This product is a 7.83HZ low frequency generator with high precisions and stability. The power supply have almost The low frequency generator and sound resonators include high stability frequency acquisition component, high-stability chip, precisions corrected capacitors, precisions multiloop adjustable resistors, and capacitors, all of which accuracy and precisions. Work and durability. resonance generator can help people relax. It help to improve the body's perception of sound and images. It also help to improve human health, improve work efficiency and mental , and improve stress. Portable, this generator is power by a 850mAh battery. Its small size makes it for use. Elevates your experience with this innovative generator. Experiment with different setting and distances to achieve the sound for your pleasure. Specifications: Material: Plastic Power Supply: 5V USB Battery: 850mah(Include) Charging Current: 250ma Operating Current: 7MA Size: About. 68x52x12mm/2.68x2.05x0.47in Package Includes: 1pc Resonance Generator note: Please allow 1-2cm errors due to manual measurement. Due to difference between different monitors, the picture may not reflect the item actual color.