1. 7.83Hz core frequency setting: Stably generate 7.83Hz electromagnetic wave pulses that are consistent with the natural resonant frequency of the Earth. 2. Portability and ease of use: Designed to be portable, easy to operate, suitable for home, office, or travel scenarios, supporting convenient functions such as USB charging. 3. Wide application: Although mainly promoted for improving sleep and relaxation, it also claims to enhance concentration, reduce stress, and optimize sound quality, the scientific evidence for these benefits is limited. 4. Easy to use: This version of Shumanbo is equipped with a power switch, so there is no need to plug and unplug the power back and forth. It can be powered by a phone charger or a power bank Type-C interface. 5. Diversified design: The circuit board has a light bulb that flashes at a frequency of 7.83 times per second, which is relatively fast and considered normal. Interface: Type-C Voltage: DC5V Frequency: 7.83HZ Product Description: This version of Shumanbo is equipped with a power switch, so there is no need to plug and unplug the power supply back and forth. Use a mobile phone charger or power bank Type-C interface to provide power. Additionally, it should be noted that there is a light bulb on the circuit board flashing at a frequency of 7.83 times per second, which is relatively slow and considered normal. Note: Installation guide not included, Please check as much as possible to make sure the item is what you need. Tips: The product may be updated constantly ,Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use Color: Black Material: PCB Package Contents: 1 x Portable Schumann wave generator Module