ArtHistoryX

One of the arms used to dock the shower-head on my sliding wall mount has broken off. I am renting, so I have no idea what brand this is, but perhaps you could advise on how to replace either just the broken part, or all of the sliding part itself. I wouldn't want to change the whole set-up, including the actual wall-mounted tube. I live in central London, near Kensington. Do you have any ideas for shops I could visit that could stock any of these parts?

Thanks