1. Made with high-quality materials, ensuring excellent frequency stability. 2. This product not only outputs a 7.83Hz Schumann wave but also incorporates programmable frequency modulation technology, allowing frequency adjustment within the range of 0.1Hz to 30kHz. 3. Two specifications are available to suit different needs: the green version only outputs a sine wave, while the black version supports sine waves, square waves, and inverted square waves. Choose the option that best suits your requirements. 4. Utilizes a digital circuit crystal oscillator frequency reference, ensuring greater stability and stronger anti-interference capabilities. 5. Power supply interface uses either a DC 5.5*2.1 or Micro USB interface for convenient use. Simply plug the USB end into a power bank, USB charger, or other USB-powered device to operate. Features: Interface Waveform: Sine Wave + Square Wave + Inverted Square Wave (Output interface is in the lower left corner, waveforms are output simultaneously) Power Supply Interface: DC 5.5*2.1 Power Supply Voltage: 5V Rated Power Consumption: <1W Default Frequency: 7.83Hz Adjustment Range: 0.1Hz~30000Hz Sine Wave Signal Voltage Amplitude: 3V Square Wave Signal Voltage Amplitude: 5V Circuit Board Size: Approx. 15*14CM Dimensions with Housing: Approx. 15.5*14.5*2.8CM Green Minimalist Version: Antenna Waveform: Sine Wave Interface Waveform: Sine Wave Power Supply Interface: Micro USB Power Supply Voltage: 5V Rated Power Consumption: <1W Default Frequency: 7.83Hz Adjustment Range: 0.1Hz~30000Hz Sine Wave Signal Voltage Amplitude: 3V Square Wave Signal Voltage Amplitude: 5V Circuit Board Size: Approx. 15*10CM Color: White Material: plastic Specification: USB cable Package Contents: 1*Schumann Wave Generator 1*USB Cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The m