Product features: 1. using high quality materials, the product has good frequency stability; 2. This product can not only output 7.83Hz Schumann wave, but also join the programmable FM technology, can adjust the frequency in the range of 0.1Hz~30KHz; 3. 2 specifications can be selected according to demand, red square wave non-adjustable frequency fixed at 7.83Hz, green standard models 0.1Hz ~ 30000Hz various frequency can be adjusted; 4. digital circuit crystal frequency reference, more stable, stronger anti-interference; 5. Power supply interface using DC5.5 * 2.1 interface, easy to use, USB end plugged into a rechargeable battery or USB charging head or other USB powered devices can work. Description: Schumann wave itself is not directly acting on the sound or video products to improve the sound quality, but the role of the spatial environment, so that the human body and mind to relax, improve the body's perception of sound and images, improve the body's health work efficiency and relieve psychological stress also has a better effect. The product not only can output 7.83Hz Schumann wave, but also can adjust the frequency in the range of 0.1Hz ~ 30KHz, digital circuit crystal oscillator frequency reference, more stable, stronger anti-interference. Product parameters: Green standard model: Circuit board size:15*15cm Antenna waveform: sine wave Interface waveform: sine wave + square wave + inverted square wave (the lower left corner is the output interface, waveform output at the same time) Power supply interface: DC5.5*2.1 Power supply voltage: 5V Rated power consumption:<1W Default frequency: 7.83Hz Adjustment range: 0.1Hz~30000Hz Sine signal voltage amplitude:3V Square wave signal voltage amplitude:5V Change the frequency method. Input the frequency directly, press the lower left key to complete the setting For example, press [7][.] [8][3], then press [OK], it can be set to 7.83Hz default power-on output 7.83Hz, setting range 0.1~30KHz How to use. Take out the product with the USB cable, round hole end connection plugged into the circuit board, USB end plugged into a rechargeable battery or USB charging head or other USB powered devices can work how Green adjustable models to change the frequency: directly enter the frequency, and then press "OK" to complete the settings Note: The product does not have a transparent plastic shell Product list: 1*Schumann wave generator 1*USB cable