They look like ordinary marbles, but they’re magnets too! Build pyramids and other fun shapes, play marble games and more. Each marble is 5/8" in diameter. Engage in magnet play, build pyramids, count, sort, and more! Bold, assorted colors. For ages 4+, grades PreK+. Each pack includes 400 marbles in a display box..Solid assorted colors.400 per pack.400 solid colored marbles in display box.Package quantity: 400 per pack.5/8" Diameter.Type: Magnetic Marbles.Ages and grades: 3-14 years ages and toddler - 9th grades.Choking hazard: Not for children under 3 years.Dowling Magnets Solid marble features 400 solid colored marbles in display box, sold as 400 per box.