1. Constructed with premium materials for excellent frequency stability; 2. Emits 7.83Hz Schumann waves and incorporates programmable frequency modulation technology, allowing adjustment within the 0.1Hz to 30KHz range; 3. Digital circuit crystal oscillator frequency reference ensures enhanced stability and superior interference resistance; 4. Features a DC 5.5*2.1mm or Micro USB power interface for convenient operation. Simply plug the USB end into a power bank, USB charger, or other USB-powered device to begin use. Product Specifications: Antenna Waveform: Sine Wave Interface Waveform: Sine Wave Power Interface: Micro USB 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 Package Contents: 1* Schumann Wave Generator (with case) 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 measurement allowed error is +/- 1-3cm.