Tuff Magnets, Super Strength Grade 8, comes with 24 3M Adhesive Dots Set, Fridge, Craft, Hobby, School, Heavy Duty. Round Disc, 3/4 inch, 50 pieces/box Grade 8, 4100 Gauss. Tuff Magnets are the strongest ceramic magnets you can buy Comes with 2 dozen super adhesive 3M VHB adhesive dots - perfect for crafts/hobbies Heavy Duty - one magnet will hold up to 12 sheets of paper to your fridge or white board 50 magnets in each box, beveled edges prevent scratching and make magnets easy to separate 3/4 inch ferrite discs are pole marked on North side for easy use at school, home, or office