Remotely monitor sensors 24/7 using a web browser*. Perfect for...Backyard temperature and humidity; Plants, gardens and greenhouses; Refrigerators, freezers; Food storage; Sensitive electronics; Outdoor pets and livestock; and so much more * Temperature and humidity measures: (1) Ambient air temperature; (2) Ambient humidity; (3) Probe temperature * Temperature range: -40°F to 140°F * Includes: sensor, DRY probe (internet gateway sold separately) * Requires 2 AAA Alkaline batteries (not included)