The pipe temperature sensor provides a real-time alert to help protect against pipe freezing. Sensor should be placed where water pipes could be exposed to freezing temperatures such as unheated basements, attics or mechanical rooms. Sensor attaches to a wall with adhesive strips that are designed to hold the sensor without damaging painted or papered surfaces or can be attached directly to a pipe with provided zip ties. Probe should be attached directly to pipe using provided zip ties making sure metal tip of probe is in contact with the pipe. Comes with 2 AA batteries installed. Dimensions: 4.375” x 2.47” x 1.12”.