Features Schumann wave generator, by nature, is an extremely low frequency (ELF) electromagnetic wave. According to the wavelength of the speed of light multiplied by the frequency, then 7.83HZ electromagnetic wave wavelength is 38,000 km, very close to the well-known circumference of the Earth 40,000 km, in fact, Tesla wave is the inherent properties of the geophysical characteristics of the earth's surface and the ionosphere constitute - an electromagnetic resonance cavity, and 7.83HZ is the inherent frequency of this resonance cavity, when the emission of such a frequency of electromagnetic waves will be in When the electromagnetic wave of such a frequency is emitted, a standing wave will be formed in the earth space, which will vibrate for a long time. Specification Operating mode: Power 7.83Hz very low frequency electromagnetic wave: 0.3mW without any sound Endurance: about 1 year Product size: 16.5*13*3.5cm Charging method: built-in 2000mA lithium battery, use the phone common Type-c interface charging (cell phone charger can be, the current is not limited) Long red light: being charged Long green light: full Blue light flashing: transmitting status Light off: shutdown / power exhaustion Supply voltage: 5V1A List 1 x Schumann wave generator 1 x Type-c power cable