The neodymium magnets are cone-shaped.The magnetic field lines are bundled on the smaller end, so that the magnets a very high magnetic force. Cone magnet neodymium are suitable for whiteboards. They holds notes securely and can be easily removed by pulling. If they are attached to a metal surface,then it is hard to remove.We almost supply all sizes of cone magnets neodymium.There must be one for you.