We offer several sizes of ferrite ceramic and neodymium magnets which are encased in ABS plastic to prevent chipping and breakage. The poles are permanently marked on the plastic cases and they are magnetized through the thickness so that one side is North pole and the other side is South pole. The sizes refer to the size of the magnet before it is encased. The ceramic magnets are high strength Grade VIII and the neodymium disk is Grade 35. Care is advised when handling these magnets to avoid being pinched by two attracting magnets.