Feature: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 GeneratorModel: FM783Material: ABSBattery: 1 x 3.7V, 600mah 503040, shipped with built in battery. .Package List:1 x Schumann Wave Generator1 x Data Cable