Feature:1. 7.8HZ GENERATOR: Ultra low frequency Schumann wave generator, resonant frequency 7.8Hz (adjustable), with high accuracy and good stability.2. EXCELLENT PARTS: Adopts highly stable pulse chip, precise correction capacitor and precise multiple loop adjustable resistor, with high reliability.3. LARGE CAPACITY: Can be used after charging, the rechargeable large capacity lithium battery can last for about 400 days after being fully charged.4. MAIN PURPOSE: Help people relax physically and mentally, improve perception of sound and images, reduce stress, and improve work efficiency.5. GOOD PERFORMANCE: The generator adopts excellent PCB components to ensure stable performance, less interference and longer service life.Specification:Item Type: Schumann Wave GeneratorMaterial: PCBResonance Frequency: 7.8Hz (Adjustable).Package List:1 x Schumann Wave Generator