The Acclima 16 Zone Decoderis used to connect 24 volt AC valves and relays to the Acclima 2-wire system. It is designed to be installed above ground either indoors or outdoors. The decoder is wired to the Acclima CS3500 controller through the Acclima 2-wire system. The 16 terminals in the decoder box can accommodate connections to 16 solenoid valves. It is normally used in retrofit installations where the zone wiring is already in place.