All Velux ® blinds made after 1968 have a plate with your model information. This can usually be found in a corner of the top of the sash. Pull your roof blind down to eye level to view, and your code should be located on the topside. This is the case for any Rooflite, Daksta, Fakro or Keylight roof blinds.
Most manufacturers supply a handy plate on their windows. However, we understand that sometimes it isn't always so clear so we've created a guide just in case. Sizes are the visible glass only.
See here for a conversion chart for codes to visible glass sizes.