Wireless base units support up to six thermostats and eight actuators (sold separately). The units receive information from the thermostats to open and close the connected actuator(s) and control the flow of water through the loops of PEX tubing in radiant heating systems or supply lines for baseboard applications. The units come with an antenna that mounts directly to the case along with a cable that can be used to remote mount the antenna outside of a metal manifold cabinet. They require 24 VAC for power which can be supplied using the A3500050 50VA transformer.