This unit is designed for either desktop or wall mounting and measures 2.5" x 5.3" x 0.6". The large liquid crystal display measures 0.5" in height. Temperature readout range is -58 to 158°F or -50 to 70°C with a resolution of 0.1°. Humidity readout range is from 20% to 95% with an resolution of 1% RH with an accuracy of 5% RH. This unit does not switch from °F to °C, you must choose either Fahrenheit or Celsius readout at time of purchase.