Wireless adapter allows easy addition of RedLINK™ enabled thermostats to TrueZONE™ systems. Use with RedLINK™-enabled TrueSTEAM™ humidification system to communicate and control humidity. Also controls dehumidifiers like Honeywell TrueDRY™. Powered by RedLINK™ reliability. No interference with other wireless devices in the home. Communicates with wireless outdoor sensor to automatically control humidity at proper levels. Dimensions: 5-9/16 inch high x 4-3/8 inch wide x 1-1/4 inch deep (141mm high x 112mm wide x 32mm deep). Mount wireless adapter on wall near HVAC equipment or on the duct. Operating humidity range (% Relative Humidity-RH): 5 to 95% RH, non-condensing. Operating temperature range: -40F to 165F (-40C to 73.9C). Color: gray. One adapter per zone control panel (HZ322 or HZ432 TrueZONE panel).