Expansion Module for ESP-Me and ESP-SMTe Series TimersEasily expand your Rain Bird ESP-Modular, ESP-Me, ESP-SMT or ESP-SMTe Series Controller with these 3 hot-swappable modules. No need for powering down the controller. Modules can be installed in any available slot on the controller. Features:Adds extra stations to RainBird residential modular controllersHot-swappable station expanding modules can be installed without powering down the controllerCompatible with Rain Bird ESP-Me and ESP-SMTe series irrigation controllers only