Take full control of your USB fan's airflow with this versatile stepless speed controller. Ideal for common 5V USB fans, cooling pads, and other low-power USB devices, this regulator lets you precisely adjust fan speed for optimal comfort and noise reduction. Whether you're working, sleeping, or just need to cool down, you can dial in the perfect breeze. Key Features & Specifications Adjustable Speed: Features a high-quality knob for smooth, stepless speed control. Wide Compatibility: Perfect for most 5V USB fans and other low-power USB-powered devices. Dual Power Input: Power the controller via a standard USB-A male plug (for chargers, power banks, PCs) or through the Micro USB port. Input Voltage Range: DC 4V ~ 12V Output Voltage Range: DC 2.5V ~ 8V Rated Power: 5W Compact Design: Lightweight and portable at just 12.75g. Note: For dual-speed fans, make sure the fan is set to the first gear before using this controller to ensure proper speed adjustment.