This is the magnetic rod in a glass jar isn't it? which picks up any loose iron particles (rust?) I've seen the demo jar, with the black stuff in it. Is it worth fitting? I've no idea, my local plumber has never suggested fitting one, so I've not bothered. I've never had a service contract either, I just have Stuart Mills to service it once a year!
ME yes, a very strong magnet but the body of the filter is black plastic. If you see one i n a plumbers they are clear, but that is so they can demonstrate how the filter works. the plumbers merchant I use said he had a fellow bring one back because it was not clear like the one in the showroom. It is said that fitting one will extend the life of your boiler, but who knows, my system had not been serviced for years, (previous owners), and the bottom of the radiators were so clogged with the sludge, there were large areas at the bottom that did not heat, so in my case, I really needed a filter to help clear the system out.
