DTM-550 SPECIFICATIONS Measurement Range: Temp:-20 °C o ~ 100 °C Humidity: 0 ~ 100%RH Temp. Accuracy: ±0.5 °C -0 °C ~50 °C , ±1°C -20°C to 0 °C , 50 °C to 100 °C Humidity Accuracy: ±2.5% RH (10% to 90% RH) ;±5% RH (<10% ,>90% RH) Operating Environment: 0°C to 50°C at <75% relative humidity Resolution: Temperature:0.1℃; Humidity:0.1% RH; Sensor: Pt385/1000Ω,RTD temperature sensor General Power Requirement: 4 pieces 1.5V (AAA size) batteries Dimensions: 6.7"x1.7"x1.6" (170x44x40mm) Weight: 6.3 oz(180g) Accessories: Soft carrying case, batteries, owners manual Certificate: CE