"I bought a pair of these expecting them to be a white version of the oak pipe collars. They are not. The oak collars latch together with dowels whereas these are dovetailed. The dovetail on one of the two collars snapped when I tried to open it. Also the oak collars are a close fit to the 15mm pipe. The holes on these are too large so they float around and look crude. (I note with interest that the catalogue image of these white collars does not show a dovetail joint - perhaps there has been a change of supplier. Not a positive one!)"