Features: .83HZ extremely low frequency pulse generators help to improve sleep, relieve fatigue and restore physical and mental. Use quality materials, the product with good frequency stability. The product can not only output 7.83Hz Schumann Waves, but also add programmable frequency technology, which can adjust the frequency 0.001Hz-200KHz. Professional oscilloscope surveyors, 7.83Hz standard sinewaves, the waveforms real and effective. Digital circuit crystal oscillator frequency reference, more stable and interferences resistant. Specifications: Material: Metal Size: about 17.0x15.0cm/6.69x5.91inch AntennaWaveform: sinewaves Power interface: USB C Interfaces waveforms: sinewaves + squarewave + inverted squarewave (the lower leftcorner is the output interfaces, and the waveforms is output at the same time) Voltages: 5V Rate power consumption: <1W Defaulted frequency: 7.83Hz Adjustment: 0.001Hz-200KHz SineSignal voltages amplitude: 3V SquareWave signal voltages amplitude: 5V Package Includes: 1x 7.83HZ Schumann Waves Adjust Signal Generator note: How to change the frequency: Enter the frequency directly, press button on the lower leftcorner to complete the setting. For example, press [7][.][8][3], then press button [OK], you can set to 7.83Hz, the defaulted power output is 7.83Hz, and the setting is 0.001Hz-200KHz.