Certainly look like 28mm, to make certain you could buy a cheap set of glass calipers or cheaper still use Freddies method, definatelty works but being Rehau I wouldn already know they were 28, I'm posh so use a Merlin laser for my surveying
When is it best to replace windows
- Thread starter volks
- Start date
This is not the window crank, just a crude way to measure it.