I made a simple hook with two magnets embedded inside. It's only used for storing keys or window remote controls.
It can be placed in the refrigerator or on a metal message board.

The size of the magnet is 10 mm long and 3 mm high.
2-story outer wall

The filling rate is 15%
Print with a 0.6 nozzle

The floor height is 0.18 mm

Insert a pause on the 19th floor

No support is needed

No specific consumables are required. PLA, PLA+, PETG... any material can be used.