This ultra-low frequency Schumann wave generator can be used in your home to reduce your metal stress, also has a fine effect on insomnia, if you suffer from insomnia, you can try this product, it will not let you down. Features: Schumann resonance (SR) is a set of spectral peaks in the extremely low frequency (ELF) portion of the Earth's electromagnetic field spectrum. This Schumann wave generator with high stability and accuracy, gives you a better using experience. You need to connect it to the power supply by type-c cable, no battery included, which is convenient to use. You can use it in your home to reduce your insomnia, you can also use it in the office to improve work efficiency. It has a wide range of uses.Easy to use, you can use it directly after connecting the power supply, whether you are a novice or an amateur, you can use it quickly.Specifications:Material: PlasticsDisc Diameter: 82mm/3.2inPower Supplies: Type-C portResonant Frequency: 7.8Hz (adjustable)Package Size: 100*82*20mm/3.9*3.2*0.8inPackage Weight: 18g/0.6ozPacking List: