This portable, professional measuring instrument features a large LCD display with backlight and multiple unit switching. It can be used for both handheld and stationary measurement. It also includes functions such as reading hold, maximum, and minimum readings. It also includes a low-battery indicator. Specifications: Air speed: m or s (meters or second): 0.80-30.0 (2.0 percent of reading and 50) ft or m (feet or minute): 78-5900 (2.0 percent of reading and 5) km/h (kilometers or hour): 1.4-108.0 (2.0 percent of reading and 50) mile or h (miles or hour): 0.9-67.20 (2.0 percent of reading and 5) knots (knots): 0.8-58.0 (2.0 percent of reading and 50) ft or s (feet or second): 1.30-98.50 (2.0 percent of reading and 50) Air volume: CFM: 0-99990 0-9.999ft2 CMM: 0-99990 0-9.999m2 CMS: 0-9999 0- 9.999 m2 Flow area setting Maximum or minimum function display Backlight automatic power off Low battery indicator Power supply: 9V6F22 battery (not included) Dimensions: (LxWxH) 17.20x8.80x4.50cm or 6.77"x3.46"x1.77" Quantity: 1 set Note: The size is measured manually, there may be an error of 0 to 2 cm, which is normal. Package includes: 1 x HYELEC MS6252A Multi-function Digital Anemometer 1 x English Manual 1 x Canvas Bag