Features: 100% new and high quality. Temperature Range: -30 Centigrade~50 Centigrade Humidity Range: 0%RH~100%RH Temperature Error: less than 10 Centigrade: ±2 Centigrade, -10 Centigrade~40Centigrade: ±1.5 Centigrade, more than 40 Centigrade: ±2 Centigrade Humidity Error: less than 40%RH: ±10%RH, 40%RH~75%RH: ±7%RH, more than 75%RH: ±10%RH Use for: Home, office, hotel, restaurant, school, meeting rooms, factories, shopping malls, warehouses, waiting room, hospital, yard, garden, etc. Humidity Calibration Method: 1. Put a wet towel to cover at the back of meter or wrap up the entire about 30 minutes. 2. At this time the meter should display the humidity readings is at 95% RH 3. If the pointer does not point to 95%RH, please use the screwdriver to open the back shroud and calibrate to 95%RH (or do not need to open the back shroud, just calibrate directly at the back of the meter) Specifications: Material: Plastic Color: White,Green Size: 22.5*6.5cm Package Includes: 1 * Analog Household Thermometer Hygrometer