A twist on a common these with these "small guitar screws" - #2 countersunk screws!

If I was to be VERY strict about this, I've only ever seen these turn up on guitars in places i would expect to see #3 screws - almost entirely cross compatible (thread diameter is 2.2mm rather then 2.4mm) but, importantly, the heads are slightly smaller on the #2s vs. the #3s. (4.2mm vs 4.7mm)

I've no idea why they turn up, or where, but, generally speaking, you can spot them on pickup rings (where they're the most common used) because the head sits further into the recess in the ring

I've seen these advertised as "vintage correct pickguard screws" too, I've absolutely no idea how true that is, but, there is a chance that they do turn up on some older guitars (I'm inclided to think Gibson personally)

Truly countersunk screws, so flat across the top face, and, as always with guitar screws, these are made from mild steel, and electroplated in a range of different colours.