Standard UPVC LETTERBOXES

Standard letter box available in 4 colours. (includes internal brushes to help reduce drafts)

Outside dimensions: 265mm X 70mm (the internal hole required is: 225mm X 45mm) 

Your outside dimensions do not have to exactly match your old letterplate but should be near to them. Your hole should be the same or slightly larger than the internal dimensions.

40mm to 80mm thickness is normally fitted to doors with the letterplate going through a midrail.

20mm to 40mm thickness is normally fitted to doors with the letterplate going through a panel

Very easy to fit providing the size is correct.  If in doubt, take your old one out and measure it.