Apresys 179-DTH USB Temperature & Humidity Data Logger USB style, reuseable, with LCD display. Temperature mearsure range -40F to 185F (-40C to 85C) with 0.8F (0.5C) accuracy; relative humidity measure range 0% - 100% RH with accuracy of +/- 3%. 1 min to 24 hours selectable sample rate. Store up to 32000 readings (16000 RH% and 16000 temp). 3 years battery life. Free software TempTrak can be download from apresys.com website.