This is a very simple 1x1 gridfinity holder for cylindrical objects. In my specific case a toothpick dispenser. The maximum diameter it can hold is 39.25 mm, and I wouldn't go a lot lower than that otherwise the object can move around too much.

The holder is 3u high, and can be printed without supports because the 6x2 mm magnet holes have bridges. Can be printed in any sort of filament you like.