TSI Alnor LoFlo balometer capture hood 6200F is the ideal way to measure very low volumetric flow. Confidently and accurately measure supply or return flows from 10 to 500 cfm. This light weight instrument is great for residential or light commercial use. The compact size allows them to be used where full size hoods would not fit such as over bathroom stalls or filing cabinets. Simulated analog display shows air trends and digital readings. Uses 4 C-size alkaline batteries; minimum 10 hours continuous use. For small diffusers, the base can be used without a hood. Includes a 16-inches length by 16-inches width, 18-inches tall hood. 32-inches height.