Schumann electromagnetic-wave is low frequency, can penetrate any material. Each person has a weak current network, which, when stimulated by The Schumann-wave, produces frequency resonance。 By receiving the Schumann electromagnetic field and the cell frequency resonance of human body, the overall balance of human meridians is maintained, so as to reduce the damage caused by EMF ionizing radiation to human body. Can induce the human body frequency resonance, complement the natural geomagnetism and the artificial attenuating electromagnetic field EMF interference, make the membrane potential balance health. Features: Built-in lithium battery, comes with micro USB cable for recharging the battery. Four lights battery indicator, it will keep flashing while recharging, 5V, 0.08A low power consumption. Sinusoidal-wave generated by programmable intelligent chip, the working frequency is 7.83Hz. The waveform, frequency, power can be set (default fixed). With higher frequency accuracy and stability consistency. The USB output port can be used as 5V power supplys. Click the switch to turn on the power supplys and display the electric quantity; Long press the switch for 5S to turn off the output. Wide applications:  Apply on audiovisual space to enhance sound field and audiovisual effects Used in bedrooms can ease insomnia. For offices it can reduce stress, anxiety, help you relax and improve working efficiency. Specifications: Name: Schumann Generator Material: ABS Color: white Battery: 1 * 3.7V, 600mAh built-in battery (included) Item size: 75 * 80 * 20mm / 2.95 * 3.15 * 0.79in Item weight: 77g / 2.72ounce Package size: 125 * 102 * 40mm / 4.92 * 4.02 * 1.57in Package weight: 103g / 3.63ounce Packing List: 1 * Schumann Generator 1 * USB Cable