These quadruple magnets work well, but they're not very strong magnets with 1.26 inch neodymium disc magnets. There are many to choose from. The ones I've used come with double strap washers so you can attach something. I attached some white oak buttons that I made from reclaimed wood (coin brick or polished stone would probably work too). You can double the magnets and get incredible holding power. 20 magnets easily hold 20 sheets of 20# copy paper.