Hidden vent for drywall ceiling

I've created ventilation outlet for hidden installation. Base should be screwed into metal profile or wooden board. Top side should be flush with drywall top surface. Use 4 magnets with bolts inside base and 4 pieces of metal(or washer) on lid. Also you should glue piece of drywall into lid and use same surface finish as ceiling. You'll get slim hollow line (~2.8 cm wide). Ventilation pipe (125mm) should be inserted into central hole and secured using screws or glue.