American Educational Products LLC has been supplying the highest quality classroom materials domestically and internationally for more than 70 years, With our creative in-house product development team, we are able to introduce new products on a yearly basis, Our products have helped teachers bring the joy of discovery, through hands-on and investigative learning styles, to generations of students, We are sincerely proud of our legacy and we promise to strive to meet the needs of present and future students as they prepare to become knowledgeable and successful world citizens, High-impact marbles have a strong magnet inside, Build shapes and designs through the principles of magnetism, Marbles are 5/8"" diameter and come in assorted colors, American Educational Products have a lead ship time of 21 days, SKU: AMED4102