Compact metal USB fan controller that gives simple, reliable control over fan speed and airflow. Key benefits: - Precise speed control lets you set the fan wind level to match personal comfort and room conditions. - Airflow adjustment reduces unwanted drafts while maintaining effective cooling when needed. - Built-in mute function minimizes operational noise for a quieter workspace or bedroom. - Low power operation at 5 V DC keeps energy use minimal while maintaining consistent performance. - Small, multifunction switch module replaces bulky controllers and adds convenience for any USB powered fan. How this product solves common problems: - Eliminates constant on off switching by letting you fine tune fan speed for comfort and power savings. - Reduces noise during work or sleep with a dedicated mute option. - Offers a compact, durable metal design that withstands daily handling and frequent adjustments. Compatibility and performance: - Designed for USB powered fans and devices that run on 5 V DC. - Inline controller provides smooth, stepless adjustment suitable for a wide range of small fans. - Metal construction for durability, with a compact footprint that fits most setups. Practical use scenarios: - Desk cooling: Quickly reduce fan noise and adjust airflow for focused work without changing fan position. - Bedroom use: Lower fan speed or activate mute for a quiet sleeping environment while maintaining gentle airflow. - Portable cooling: Attach to USB fans used with power banks or laptops to balance cooling and battery life. Specifications: - Material: Metal. - Color: As shown in the product image. - Size: As shown in the product image. Note that 1 inch equals 2.54 cm. - Operating voltage: 5 V DC. - Package includes: 1 USB fan controller. Notes: - Actual item color may vary slightly due to monitor display and lighting conditions. - Please allow a measurement tolerance of 1 cm to 2 cm due to manual measuring.