The magnetic field observation sheet is a sheet for visualizing magnetic fields (magnetic field) that are not visible to the human eye. When you place magnets and magnets (such as motors, speakers, etc.) on this sheet, you can observe the magnetic field of objects that you put on the sheet with magnetic patterns. You can also see the magnetic patterns on the magnetic recording media such as tickets for commuter passes and tickets for automatic ticket gates. Sheet Size: 6.9 x 7.9 inches (175 x 200 mm), Rubber Bar, Magnetic, Instruction Manual Included, Can be used repeatedly. Can be cut with scissors.
(From Amazon.co.jp)