The super-strong rare-earth square magnets are perfect pieces for DIY projects and for building 3D puzzles out of magnets. The magnets can create and recreate an outrageous number of shapes and patterns. They are super strong rare-earth magnets - once they get stuck with each other they are hard to break apart. - Note : due to new postal shipping regulations DX is now adding significantly more packaging material to pack these super strong magnets. This also ensures safe and speedy delivery of the magnets. . For significantly better value a 100-pack package is available. . - Super strong RE (Rare Earth) magnet -- once they get stuck with each other they are hard to break apart - Electrically conductive (making them suitable to extend recessed batteries) - 1mm thick 10mm in diameter