The C-2220 high-low pressure selector selects and transmits control pressure signals from a group of thermostats or controllers. The appropriate C-2220 module must be selected to work with either high or low volume thermostats or controllers. The C-2220 high-low pressure selector can be combined in master and slave module groups for applications using both high and low volume output thermostats or controllers.

• One master can combine with as many as 19 slaves to control 20 zones