Suitable for improving inspiration when thinking Consolidate your memory while you sleep Product size is compact and easy to carry Stimulates the brain into deep sleep Suitable for stabilizing the mind while meditating Features: The 7.83HZ Schumann Wave can help people relax physically and mentally, improve body health and work efficiency, reduce mental stress. The 7.83HZ Schumann Wave Ultra-Low Frequency Pulse Generator is of high accurancy and stability. The pulse generator is adopted with high stable frequency acquisition elements, precision correction capacitance, precision multi-loop adjustable resistor, display solid capacitance. Equipped with high-quality lithium polymer battery, with overcharged, over-voltage, over-current protection. There is almost no voltage ripple in the voltage supply. You can apply it in your bedroom, office, study, tea room and so on. It is normal for each person to experience different results Color: Green Material: plastic+metal Package Contents: 1 x host 1 x charging 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.