I only got this unit recently and have had it for a few days. So far so good. This unit comes with a sensor bullet and a controller with about 16 ft of cable. The bullet sensor is placed in the water and then the controller is connected to an I/O linc. I set the temp on the controller and so far it is triggering like I wanted I have a small pump and heater. It takes a bit of trial and error to get it set where you want, but I didn't find it too cumbersome because I wasn't sure what exact temp I wanted it to turn on and off. You need to protect the controller portion from the weather but you need to do that for the I/O linc as well. I used one of those plastic covers that mount to an outdoor socket from Home Depot. The sensor part itself sits in the water. Our climate here is tough on anything outdoors but this unit appears well built. I hope to update this after a few seasons.