is it possible to attach or bolt on cup magnets to the bottom of this box?
EDWARD W Yes. If you bolt them on you will loose water tight integrity unless you seal the bolts with silicone glue but IMHO that should work. Andy
SANDRA F If you bolt anything to it, wouldn't it no longer be water tight? You could put a magnet inside or glue them to the bottom if you're looking to attach it to stay.