I also bought a '100mm wall plate' (http://preview.tinyurl.com/2fjgf8g (or <http://www.toolstation.com/shop/Electrical/Ducting/100+Round+Wall+Plate+100mm/d190/sd3083/p79588>) to tidy things up on the inside wall, and to hide the damaged plaster/brickwork.
However, the hole in the wall plate is actually 110 mm. Therefore the matching ducting (od about 103mm) passes through the hole with a gap of about 4mm all round. In other words, the area most damaged is completely exposed. I was expecting it the ducting to be a snug fit through the hole. I contacted Toolstation about it, under the impression that the product was wrongly labelled or something, but was assured it was correct and was referred to the manufacturer's product support line. It was obvious I wasn't the first person to call with this issue, but no explanation was forthcoming other than a shrug of the shoulders.
Has anyone else come across this bizarreness? Or am I doing something totally stupid here?