Set of 100 Small 12mm Glass Marbles, Assorted Colors, For Marble Run, with Marble Jar For Storage With marble jar for easy storage and endless fun anytime, anywhere! Size is 12mm. Top line quality glass marbles: all marbles in the container are constructed upon the highest quality standards. Therefore, they are made to be top-notch and exceed your highest expectations! For super fun games like the marble run or the traditional marble game that boost your childs hand-eye coordination and develop useful fine motor skills! Also great for sling shot ammo! Incredibly versatile toy: children have been playing with marbles for thousands of years  they are a toy that will never fall out of fashion! Assorted 12mm peewee marbles: get the most beautifully made, colorful marbles in existence - playing with marbles is a cheap and cheerful activity that will keep your little ones entertained for hours!