I think I've only ever seen Americans mention the electromagnet-on-a-wall type of device for holding open fire doors.
Are you allowed the type that screw to the door and push a peg into the ground over there? They're meant to let go if they hear the alarm.
https://www.screwfix.com/p/dorgard-ll800-hold-open-fire-door-retainer-black/37858
@InsertUser Looking at your posts it appears that you’re in/from Belgium? Your neighbors to the north have the electro magnets everywhere in institutional buildings (government, hospitals etc)