Welcome to our shop! The product we have is the Schumann wave 7.83HZ extremely low frequency generator. It is a rechargeable model, small and portable in size. It comes with a 20CM / 7.9in charging cable for your convenience. This generator uses a new optimized circuit design and gold-plated launch circuit, ensuring high accuracy and stability. It has wide applications, such as generating wave signals for experimental development, controlling motor drivers, generating adjustable pulses for MCU, and controlling relevant circuits (such as PWM dimming speed applications). Being rechargeable, this generator promotes a greener world. Its compact size makes it easy to carry around. It also has nearly no voltage ripple, allowing for more accurate output frequency. The charging current is 250mA, and the product can be fully charged in about 6 hours. The working current is about 7mA, and it can be used for about 200 hours (168 hours a week) when fully charged. In the package, you will receive: - 1 x Schumann Wave Pulse Generator Module - 1 x USB Line - 1 x Screwdriver 100% Satisfaction: Our customers are our top priority. If you find any product problems after receiving the goods, such as damage and incorrect quantity of goods, please contact the seller immediately. We try our best to provide you with satisfactory after-sales service. Thank you for choosing our shop!