If you have any interest in working on things, a ~$30 set of calipers is an awesome tool for figuring out hardware sizes and so much more. You can definitely spend much much more but as a hobbiest I'd recommend against it.
A few spare charging cables to keep plugged in around the house are always great too, I also recommend keeping one in your travel bag so you never need to think about packing one.
I meant like USB-C/lightning, for misc mobile devices haha.
A recharge set of calipers actually sounds pretty horrible. Imagine trying to finish a project and waiting on them to charge for a single measurement.