Use double-sided tape produced by Guwei Company instead of magnets. If it becomes dirty, you can wash it with water and re-paste it many times. However, it does not have the same automatic suction force as magnets. Using this double-sided tape can greatly reduce the cost of magnets. In terms of cost, magnets are also expensive now. For example, the door switch of a water dispenser can be replaced. (Guwei GW-003B double-sided tape)