I'd steer clear of them...I've heard a lot of negative comments about them (fires, not working after only a short period of time, etc). I use the Home Depot timers, possibly the same ones Val is talking about (although "splitter type thingy does leave some room for interpretation), on systems I don't have a controller on (IMO controllers are the way to go if you can afford one). Even with the enormous humidity issues I deal with all the time, the Home Depot timers have been very reliable.