Wireless Adapter allows you to easily add RedLink-enabled thermostats to a TrueZone system without running new wires. Use a RedLink-enabled TrueSteam Humidification System in gray with a wireless adapter to communicate and control humidity from Prestige without running new wires to the living space. Prestige also controls whole-house dehumidifiers like the Honeywell. Wireless Adapter allows you to easily add RedLink enabled thermostats to a TrueZone system without running new wires. Mount wireless adapter on wall near HVAC equipment or on the duct. Terminal Designations: A, B, C and D. Dimensions: 5.56 inches high x 4.38 inches wide x 1.25 inches deep, 141 millimeters high x 112 millimeters wide x 32 millimeters deep. Operating Temperature Range: minus 40 to 165 Fahrenheit, minus 40 to 73.9 Celsius. Operating Humidity Range: (% relative humidity), 5 to 95% relative humidity and non-condensing. Requirements: One adapter per zone control panel, HZ322 or HZ432 TrueZone panel.