Our unique fingering chart magnets were created with the visual learners in mind. They work like a stencil, with holes cut in the magnet where the instrument’s keys/valves are located. When applied to any magnetic dry-erase board, the teacher indicates and displays the correct fingering by using a dry-erase marker to fill in the cut-out area. The primary writing surface is the dry-erase board, not the magnet. This design, with normal use, will last for years!