Specification working principle: The wind blows the paddle on the generator shaft to rotate, and when a certain speed is reached, the motor starts to generate electricity. The higher the rotational speed, the greater the generated voltage. Note that it typically requires airflow from a device such as a hair dryer to achieve higher voltage output, as natural wind may not provide sufficient force. Micro generator: 1. When wind speed is sufficient, the motor generates voltage without connecting LED lights or other loads. The no-load voltage can reach approximately 20V. 2. The motor features a built-in USB socket, allowing direct connection to the included USB light. It may power other low-power USB devices, but performance is not guaranteed. Charging smartphones or power banks is not supported due to the absence of a voltage regulation module. 3. When equipped with a regulated 5V module, the charging current is approximately 30mA under maximum airflow from a household fan. For a smartphone with a 4000mAh battery, the theoretical charging time would be around 6 days. (Note: Market-available micro wind generators are generally not capable of effectively charging mobile devices. Even if minimal current is detected, practical charging is not feasible.) Length: 18cm [Inner hole] 2mm (for secure fitting) Material: ABS plastic Weight: Approximately 4.8 grams [Installation] Equipped with positive and negative paddles, designed to be fixed onto a motor shaft with a 2mm diameter. Usage: Lights up when exposed to airflow; can be mounted on a bicycle to generate light while riding. Includes a USB light with a 1-meter cable and 5-watt output, compatible with power banks for emergency lighting. Product includes: 1 x Micro Wind Generator, 1 x USB Light Bulb