An ultra-quiet UL-certified fan system designed for cooling cabinets that requires minimal noise. Features a multi-speed controller to set the fans speed to optimal noise and airflow levels. Contains a CNC machined aluminum frame with a modern brushed black finish. Powered by wall outlet or USB port, included Turbo Adapter increases performance by 25%. Dimensions: 8.5 x 4.4 x 1.3 in. Total Airflow: 52 CFM Total Noise: 18 dBa Bearings: Dual Ball