Super Strong N52 Neodymium Magnet 3 x 1/2 x 1/4" Bar, The World's Strongest & Most Powerful Rare Earth Magnets by Applied Magnets: Amazon.com: Industrial & Scientific
CMS Magnetics® Grade N52 Super Strong Neodymium Magnet Ring OD1.26" x ID 1/2" x 3/8" - Rare Earth Magnet Ring for Classroom, Science Project and DIY Applications - One Pack: Amazon.com: Industrial
daw21onlineshop Neodymium Magnet N50 30x10x2mm Cuboid Block 1 Very Strong Magnets for Glass Magnetic Boards, Magnetic Boards, whiteboards, blackboards, pin Boards, refrigerators: Amazon.com: Industrial & Scientific