From what is written in the description and from what the seller told me (I contacted them, but their English is worse than mine) these are COA stickers with product keys and accompanying install CDs/DVDs from used Dell desktops, meaning OEM installs, but they somehow weren't activated.
I thought that OEM licenses cannot be transfered to new machines? What's confusing is that people seem to be buying these licenses and the seller has thousands of positive feedback points left. I'm asking more out curiosity, but if this is legal and if it will work properly, I might get a Windows XP license to run some older games that just don't work properly or can't run at all on Windows 7/8. What do you guys/gals think?