The TR70 Zio and Zio Plus series wall modules are 2-wire, polarity-insensitive devices communicating via a Sylk bus for use with Spyder® and ComfortPoint™ programmable controllers. All models are equipped with a room temperature sensor, a network bus jack, and an LCD panel with three function keys and two Up/Down adjustment keys. The TR7-H, TR71-H, and TR75-H models include a built-in humidity sensor.