Use the table below to determine the best Irrigander expander or combination of expanders for your application. Note that this table is for a set of field wires running to a particular set of valves. There can be other sets of valves in the system. The Irrigander 4 and Irrigander 8 series expanders do not use the system common so field wires must be dedicated to the connections between the Encoder and the Decoder. The Irrigander Pro series expanders use the system common connection as one of the field wire connections so only one of the two required field wires is dedicated to the connection between the Encoder and the Decoder (the common can be shared with other valves or other Irrigander Pro expanders). See the application note "Configuring Irrigander Systems" for more information on installing Irrigander expanders. This application note is available in the Support section of our website. Please contact our team if you have any application questions. They will be happy to help determine the best configuration of Irrigander expanders to provide a solution to meet your needs.