Kangnice HYELEC MS6252A Wind Speed Meter LCD Digital Anemometer Air Flow Test Backlight This meter is a portable, professional measuring instrument with large-screen LCD and backlight, multi-unit switching functions.This meter can be used for hand-held or fixed measurement. This meter has the functions of reading hold, maximum, minimum, etc.It has a low battery indicator . Wind velocity:m/s(meter per second): 0.80~30.0 (2.0% reading+50),ft/m (feet per minute): 78~5900 (2.0% reading+5) km/h (kilometer per hour): 1.4~108.0 (2.0% reading+50).mile/h(mile per hour): 0.9~67.20 (2.0% reading+5) Power supply: 9V6F22 Battery(Not Included),Size: (L*W*H)17.20*8.80*4.50cm/6.77"*3.46"*1.77"