In search of safe magnets to use in the classroom or in a children's environment? Hero Magnets to the rescue! Chunky size with magnets completely encased in plastic. Strong display magnets help you get, and stay, organized. Great for whiteboards, filing cabinets, fridges, and more. Each set includes 12 bi-color magnets--flip them over to see a different bright color! Set of 12. Big Blocks measure 2L x 1W x .50T and hold 20 pieces of paper.