Extech 45170 Four in One Environmental Meter (Hygro-Thermo-Anemometer-Light) Pocket size rugged 4-in-1 meter for humidity, temperature, air, velocity and light Ergonomic pocket size housing with large dual LCD simultaneous display of temperature and air velocity or relative humidity Characters on display reverse direction depending on Hygro-Thermo-Anemometer or light mode Data hold to freeze the displayed value Records Min/Max readings