1. Adopting high-quality materials, the product has good frequency stability; 2. This product can not only output 7.83Hz Schumann resonances wave, but also add programmable frequency modulation technology, which can adjust the frequency in the range of 0.01Hz to 100000Hz; 3. Digital circuit crystal oscillator frequency reference, more stable and more anti-interference; 4. The power interface adopts a DC5.5 * 2.1 interface, which is convenient to use. The USB end can be plugged into the power bank, USB charging head, or other USB powered devices to work. Schumann resonances itself does not directly act on sound or video products to improve the sound quality, but on the space environment, which can relax the body and mind, improve the body's perception of sound and images, improve the health work efficiency of the human body, and relieve Psychological stress. This product can not only output 7.83Hz Schumann resonances wave, but also adjust the frequency in the range of 0.01Hz~100KHz. The digital circuit crystal oscillator frequency reference is more stable and more anti-interference. Green standard version: Circuit board size: 15 x 15cm Antenna waveform: sine wave Interface waveform: sine wave+square wave+inverse square wave (the bottom left corner is the output interface, and the waveform is output simultaneously) Power supply interface: DC5.5 * 2.1 Power supply voltage: 5V Rated power consumption:Less than 1W Default frequency: 7.83Hz Adjustment range: 0.01Hz~100000Hz Sinusoidal signal voltage amplitude: 3V Square wave signal voltage amplitude: 5V Change frequency method: Directly input the frequency and press the bottom left button to complete the setting For example, by pressing [7] [.] [8] [3] and then [OK], you can set the default power on output to 7.83Hz, with a range of 0.01Hz~100KHz Colour:green Material:PCB Package Contents: 1 x Schuman