General Tools HT08 Mini USB Temperature Humidity Data Logger Ideal for water damage restoration, process control and environmental monitoring; one button starts/stops logging without a PC Includes disc with drivers and software used to set sampling time from 10 seconds to 12 hours; Hi and Lo alarm setpoints for humidity and temperature Software also calculates GPP/GPK mixing ratio, dew point and wet bulb temperatures Stores more than 16,000 pairs of RH and temperature readings; one click exporting of logs to Excel Power source is 2 AA batteries (included)