Zoo-Med Digital Combo Thermo/Humidity Gauge combo unit for use in terrariums or other pet animal applications. The sensors for humidity and temperature are independent so can be used in different locations. The temperature probe is waterproof so can be used to monitor water temperatures, but the LCD display must be kept dry. Temperature range -20 to +60C. Both probes can be affixed with the suction cups provided. Uses one LR44 battery which is included.