Ring neodymium magnets with holes in the side are typically a type of magnet that has a ring-shaped profile with holes in the side, and are of a special customized type, a design that is common where specific mounting or use conditions are required because the holes in the side allow the magnets to be mounted in a device in a specific way. For example, the holes can be used to secure the magnet to a mechanical structure or to pass other components through the holes to interact with the magnet.
Other classic side magnets with holes;
N52 Strong Countersunk Ring Magnets With Side Hole
Strong cylindrical magnet with side hole [custom sales supply]