The Schumann waves generator itself does not make any sound, and it is not directly acting on the sound or video products to improve the quality of sound or vision, but it plays a role in the space environment, it can help relax people's physical and mental, and it helps improve the body's perception of sound and imaging, and it also helps the human body more healthier to improve the work efficiency, and the condition of mental stress also has improved. Specifications: Name: Schumann Resonance Generator Material: ABS Type: without housing, with housing (optional) Power: 5W Frequency: 7.83Hz Input power: 5V Interface: USB Item size: 102 * 80 * 18mm / 4.02 * 3.15 * 0.71in Package size: 195 * 130 * 30mm / 7.68 * 5.12 * 1.18in Package weight: Without housing: 66g / 2.33ounce With housing: 164g / 5.78ounce Packing List(without housing): 1 * Schumann Resonance Generator 1 * USB Cable OR Packing List(with housing): 1 * Schumann Resonance Generator 1 * USB Cable 1 * Transparent Housing