Why is the page height 242 mm?

Currently, the template contains the following:

\settrimmedsize{242mm}{165mm}{*}

Recently I got a cropped version of my thesis from LiU-Tryck, and it was 2 mm shorter for some reason. I asked them, and they replied the following:

Avhandlingar görs i formatet 165x240 mm, och mallen du använder är 165x242 mm. Boken blir alltså 2 mm kortare på höjden jämfört med mallen.

Why is it 242 mm in the template?