1.accurate humidity 2.dual display, 3.backlight ... AAA battrries only. SPECIFICATIONS:.Measure Parameters: °C, °F, %RH(relative humidity), td(dew point temperature).Range: -10 ~ +50 ... +100%RH.Resolution:0.1°C, 0.1°F ; 0.1%RH .Accuracy: ±1.0°C, ±1.8°F, ±3%RH(5~95%RH).Sample Rate:1 time sec ... : DC1.5V (AAA) x 3pcsAccessories include: . Free 1.5V x3AAA batteries .Free protect cover .Free protective carrying ...