Features: 7.83HZ Waves-This product is a Pulse waves 7.83HZ extremely low frequency generator with high accuracy and stability. High stability frequency acquisition components, high stability pulse chip, accurate correction capacitors, accurate multi‑loop adjustable resistance, shielded solid capacitors. Adopt newly optimized circuit design, gold-plated transmitters circuit. Let people relax physically and mentally, improve the human body's perception of sounds and images, improving human health, enhances the work efficiency, and have a good effect on mental stress. Crafted from ABS, impacts resistance, environmental protections, heat resistance and low temperature resistance. Specifications: Material:ABS Diameter:13cm/5.11'' Package Includes: 1Set Pulse Resonance Generator note: Please allow 1mm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual color.