In this home i bought, the back yard 28 zone system had a gray 3" diameter by 2" high plastic cylinder lying on the ground with a wire bundle going to a valve box in the ground near the wall mounted controller. Some of the zones off my hunter controller are also hooked up to a wire bundle and not the normal red wires and they go to this same valve box. I have not dug into the valve box yet so it all appears to be related to this cylinder and a valve in the box. Everything seems to work ok but I ...
