This product is Schumann .83HZ very low frequency generator, features high accuracy and stability.High stable frequency acquisition elements: high stability pulse chip, precision correction capacitance, precision multi-loop adjustable resistorSchumann wave itself is not directly acting on the sound or video products to improve the quality of sound quality, but the role of the space environment, people's physical and mental relaxation, improve the body's perception of sound and images, improve the health of the human body to improve the efficiency of work, mental stress also have a better effect.For audio-visual space - to enhance the sound field and audio-visual effectsFor the bedroom - to help sleep soothe the nerves, treatment of insomniaFor the office - relax and improve work efficiencyFor the create space - to improve inspirationFor the tea ceremony, spirituality, realization space - resting body and mindFrequency:7.83HzRated voltage:DC 5VRated current:0.5ANotice:The Switch only for the indicator light ON/OFFColour:BlackMaterial:PCB+electronic componentsPackage Contents:1 * 7.83HZ Schumann Wave Generator(With DC-USB cable)Only the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.