Features 1、More Relaxation: Improves sound field and audiovisual effects, relieves insomnia, reduces stress, anxiety, and helps you relax. 2、Smart Adjusting: Waveform, frequency, power can be adjusted, has higher frequency accuracy and stability consistency as well. 3、.Lower Frequency: With a programmable smart chip, the Schumann generator can generate a sine wave with 7.83Hz ultra low frequency. 4、Simple Charging: The built in lithium battery can be charged through the USB port, has 4pcs indicator flashing when charging. 5、Reliable in Use: Comes with 5V and 0.08A low power consumption, the audio resonator can applied to office, bedroom and so on. Specification Item Type: Schumann Wave Generator Model: FM783 Material: ABS Battery: 1 x 3.7V, 600mah 503040, shipped with built in battery. Package List 1 x Schumann Wave Generator 1 x Data Cable