Feature: 1. Accuracy Correction Capacitor: Made of high stability pulse chip, accuracy correction capacitor, and accuracy multi loop adjustable resistance. 2. Large Capacity Lithium Battery: Rechargeable large capacity lithium battery is used, which can be used for about 400 days after a full charge. 3. Improve Human Health: Beneficial to people physical and mental relaxation, improves the human body's ability to perceive sounds and images, and enhances human health. 4. Good Stability: Can improve work efficiency, reduce mental stress, ultra low frequency, high accuracy, and good stability. 5. Working Status Indicator Light: With working status indicator light (red, green or frequency flashing blue light), you can clearly see the working status. Specification: Item Type: Ultra Low Frequency Pulse Generator Material: PCB+Acrylic Board Purpose: Used for relaxing sleep and improving the body perception of sound and images Frequency: 7.83HZ Rated Voltage: DC 12V Rated Current: 0.5A Power: 0.3mW Working Mode: 7.83HZ Extremely Low Frequency Electromagnetic Wave, Without Any Sound Battery Type: Lithium Battery (Shipped with built in battery) Battery Model: 2000mAh Lithium Battery Nominal Battery Capacity: 2000mAh. Package List: 1 x Schumann Wave Generator1 x USB Data Cable Note: If the battery is insufficient, please charge in time to avoid bad experience.