Features: Adopted of Mini Usb port power supply, typically+5V 0.1A, and comes with USB cable ultra-low static power consumption main control IC, to make the waveform more stable Output 7.83HZ pulse square wave, whose duty cycle is 50%. Frequency can be fine-tuned for correction This product is Schumann .83HZ very low frequency generator, features high accuracy and stability. For audio-visual space - to enhance the sound field and audio-visual effects, For the bedroom - to help sleep soothe the nerves, adjust insomnia, For office - to relax and improve work efficiency, Used to create space - to improve inspiration, For the tea ceremony - resting body and mind Specification: Power supply: +5V Current: 0.1A Pulse square wave: 7.83HZ Material: PC+Metal colour: As Shown Package Contents: 1 x Pulse Generator 1 x 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.