Features 1、Using DDS algorithm, the frequency step value can be up to 0.001Hz, good frequency stability. 2、This product can not only output 7.830Hz Schumann wave, but also increase the programmable frequency modulation technology, can be adjusted in the range of 0.001Hz ~ 200KHz frequency (can also be used as an ordinary programmable digital signal generator). 3、Digital crystal oscillator frequency reference, more stable, more anti-interference; 4、Power supply interface using DC5.5*2.1 interface, easy to use, USB terminal can be inserted into the power supply or USB charging head or other USB power supply device work. Specification Schumann itself does not directly act on the sound or video products to improve the sound quality, but acts on the space environment, can relax the human body and mind, improve the human body's ability to perceive the sound and image, improve the human body's health and work efficiency, and alleviate psychological stress. The effect is better. This product can not only output 7.830Hz Schumann , but also can be adjusted in the range of 0.001Hz ~ 200KHz frequency, digital circuit crystal oscillator frequency reference, more stable. Features: Using DDS algorithm, the frequency step value can be up to 0.001Hz, good frequency stability. This product can not only output 7.830Hz Schumann , but also increase the programmable frequency modulation technology, can be adjusted in the range of 0.001Hz ~ 200KHz frequency (can also be used as an ordinary programmable digital signal generator). Digital crystal oscillator frequency reference, more stable, more anti-interference; Power supply interface using DC5.5*2.1 interface, easy to use, USB terminal can be inserted into the power supply or USB charging head or other USB power supply device work. Instructions For Use: Take out the USB cable that comes with the product, connect the round hole end with the circuit board, and plug the USB end into the power bank or USB charging head or other USB powered devices to work. Change the frequency: directly input the frequency, press "OK" to complete the setting. How to Change the Frequency: Input the frequency directly and press the lower left button to complete the setting; For example, press [7][.] [8][3], then press [OK] to set to 7.83Hz, the default power-on output is 7.83Hz, and the setting range is 0.001~200KHz. Specifications: Material: ABS Circuit Board Size: 14 * 15cm Antenna Waveform: Sine Interface Waveform: Sine + square + inverted square (the lower left corner of the output interface, while the output waveform) Power Supply Interface: DC5.5 * 2.1 Power Supply Voltage: 5V Rated Power Consumption: <1W Default Frequency: 7.830Hz Adjustment Range 0.001Hz~200KHz Sine Signal Voltage Amplitude: 3V Square Signal Voltage Amplitude: 5V Package Weight: 180g / 6.35oz Package Size: 15 * 15 * 3cm / 5.91 * 5.91 * 1.18in Package List: 1 * Schumann Generator 1 * USB Cable Package List 1 * Schumann Generator 1 * USB Cable