A complete fan kit designed for cooling and ventilating cabinets that require minimal noise * Features a stainless aluminum frame with a brushed black finish and an on/off switch * Can be powered by wall outlet or USB port, a plug adapter is included * Each unit contains an additional USB port, up to 4 fans can be daisy chained together to share the same power source (dual units count as 2 fans) * Total Size: 11 x 5.75 x 1.5 in; Each Fan: 4.7 x 4.7 x 1 in; Total Airflow: 104 CFM; Total Noise: 26 dBA; Bearings: Dual Ball