Consolidate your memory while you sleep Product size is compact and easy to carry Suitable for improving inspiration when thinking Stimulates the brain into deep sleep Suitable for stabilizing the mind while meditating Use Introduction. Available Type-C interface universal cell phone power cord plugged into the interface energized, the indicator light is on can be used, do not need any adjustment operation;. Schumann wave suitable for quiet environment space, directly flat or vertical: placed on the desktop about 1 meter high, about one meter away from people. A Schumann wave generator is suitable for about 10 square meters of space range, the space increases, the number of Schumann wave generator should also be increased. (Friendly reminder: this instrument has no battery can not be charged, connected to the USB cell phone charger can be, unlimited current ) It is normal for each person to experience different results Color: Black Material: plastic Package Contents: 3 x Main unit (Need Type c cable no include)