Resideo THM5421R1021 2-Wire IAQ Equipment Interface Module RedLINK
The Resideo THM5421R1021 is a 2-Wire IAQ Equipment Interface Module designed to integrate indoor air quality accessories with RedLINK-enabled HVAC systems. It acts as a wireless control bridge, allowing thermostats to manage humidifiers, dehumidifiers, ventilators, and other IAQ devices using a simple two-wire connection.