Widely used: Schumann wave generator provides sine wave, square wave and reverse square wave options. The attached acrylic dust cover helps protect the circuit board. Adjustable frequency: You can customize the frequency from 0.01 Hz to 90,000 Hz to improve efficiency and make customization. Stability: Schumann wave generator can ensure stable frequency output, with standard value of 7.83 Hz, sine wave voltage amplitude of 3 V and square wave voltage amplitude of 5 V. Compact structure, easy to carry: Schumann wave generator is small, only 15x15, powered by USB, easy to carry at home or when traveling. Promote relaxation: Schumann wave generator can emit sine waves, create a relaxed and pleasant environment and promote physical and mental pleasure. Description: This product is an ultra-low frequency Schumann wave generator with a frequency output of 7.83 Hz, stable frequency, and equipped with USB cable. It is convenient to use, small in size, convenient to travel or carry around, and helpful to relax and enhance happiness. Product name: Schumann wave generator The adjustment range is 0.1 Hz - 99999 Hz. Voltage range of sine wave signal: 3V; voltage range of square wave signal: 5V Power interface DC 5.5 x 2.1 Nominal power consumption: Less than 1W Antenna waveform: sine wave Interface waveform: sine wave+square wave+inverted square wave (output interface in the lower left corner, waveforms are output at the same time). Color:As Shown Material:PCB Package Contents: 1 x Schumann wave generator (with acrylic shell)