What are Rain Bird ESP-SMTe Expansion Modules? These units allow your modular Rain Bird ESP-SMTe controller to expand to control more valves than the basic three-valve module which comes with the controller.

You must have an ESP-SMTe controller for these units to work. If you are looking to upgrade your controller to a smart-controller, the Rain Bird ESP-SMTe is an excellent choice. And, for now, rebates are widely available for such upgrades.