1. Using High-Quality Materials, The Product Has Good Frequency Stability. 2. This Product Can Not Only Output 7.83Hz Schumann Waves, But Also Adjustable Sine Waves From 0.01Hz To 9999Hz. 3. This Model Adopts A 4-Digit Digital Tube Display For Clearer Display. 4. Connect The Type-C Power Supply, The Digital Display Shows 7.83, And The Board Will Automatically Emit A 7.83Hz Schumann Wave. 5. The Power Interface Adopts Type-C Usb Interface, Which Is Convenient To Use. Shumanbo itself does not directly act on sound or video products to improve sound quality, but rather acts on the spatial environment to relax the body and mind, enhance the body's perception of sound and images, improve the efficiency of human health work, and relieve psychological pressure. This product can not only output 7.83Hz Schumann waves, but also adjust the frequency within the range of 0.01Hz-9999Hz. The high-speed DAC can generate pure sine wave signals. Parameter: Working voltage: DC 5V Working current: 14-17MA Power interface: Type-C (supports Type-C to Type-C power supply) Default frequency: 7.83Hz Adjustment range: 0.01Hz-9999Hz pure sine wave Signal voltage amplitude: 3V With 3.5MM audio output Basic Function Introduction: 1. Double sided ultra long antenna 2. Overcurrent and overvoltage protection 3. 3.5MM audio interface 4. Dedicated pure sine wave chip 5. High speed operational amplifier Colour:White Material:PCB+Components Due to different batches, there may be differences in product appearance and printed text, which will not affect use Package Contents: 1 * chumann Wave Generator 1 * USB cable(USB cable color random,, don't accept the specified color)