Highlights - 1.System Compatibility - This marble run set works with marbles up to 16mm in diameter. In addition to the marbles included, kids can mix it up with marbles from other brands for endless racing fun and exploration! 2.Glowing Marbles - Get ready for some glow-in-the-dark fun! Our marble race track comes with glowing marbles that shine bright, adding a new level of excitement and long-lasting enjoyment. 3.Fun 3-in-1 - This marble run is more than just a toy set! Our building blocks an