Gift ideas

A small pen knife shaped multi tool but having looked online at the prices I think they're a bit too expensive for an advent calendar.

https://www.amazon.co.uk/LND-GIFTS-Stain...d_source=1

Post it notes or stationery of his liking.
Does he wear specs? Glasses cleaner.
A leather strip for his ponytail (I'm assuming he still has one)

 I like the pocket hero. That looks cool toy.
He does wear glasses, lens cleaner is a good idea.
He does still have long hair. But it’s cheap and cheerful hair bands. That gets replaced when the elastic has packed its bags and left home . He’s got a bag of a 100 . I could put some of those in. But things like that would never get put away by anyone other than me   .