This is a little magnetic storage box for a spare Elegoo Neptune 4 plus/max extruder. It uses 10x2mm neodymium magnets and a stop that slides into place with a dovetail. The dove tail should be tight enough to not need glue. the magnet holes are tight tolerance for a snap in fit. only one of my magnets needed glue. You could also use 10x3 or 10x4 to get more hold and clearance for screws.
Prints without supports. Use 3 walls and 15% adaptive cubic infill. 

Printed in Elegoo pla+, and yes I need to clean my build plate, I know.