The Resideo REM5000R1001 Portable Comfort Control is a convenient device that allows you to easily control the temperature in your home. This tiny white unit (6.25" x 3.12") is intended to function in tandem with compatible RedLINK thermostats and accessories. Whether you have a zoned or non-zoned HVAC system, this control provides unmatched convenience. https://www.partshnc.com/rem5000r1001-resideo-portable-comfort-control