would be a module that has an antennae protruding from it but no dials in the front, all it does is take the wired signal and converts it to a wireless signal to be used with wireless devices, also works with wifi modules (which will end up the next module type suggestion).
This is great for the previous suggestion of a sprinkler timer that is remotely controlled from inside the house. It might be out of range for me to control it from my upstairs master bedroom in the upstairs-back-northwest side of the house, when the timer would be located at the downstairs-front-southeast side of the house. I would plug the module into a socket that both has the wireless range and that works good with the wired control and this would be a great comfort. turning it off manually right from my bedroom.