The High Wall is flexible to fit any application from 38MPRB single zone or the 38MGRB multi-zone system. Talk about controllability, the 40MPHB indoor unit features either built-in Wi-Fi^® that gives you control from virtually anywhere or compatibility with third party thermostats when the 24V Interface is installed. The High Wall also offers a Relative Humidity Sensor to customize the humidity level for more comfortable air and an occupancy sensor that senses a person in a room and can direct airflow either toward or away from that person.