These balls are really cool.  My son picked out a glitter one that lights up when it is bounced 4 months ago for a birthday present when they were 50% off.  Just a warning though, the balls will start to get soft overtime with use.  You should inspect these after awhile to make sure they don't crack.  A friend of mine said hers exploded one day when her kids were playing with it.  Mine hasn't cracked or exploded yet but it is getting quite soft and weak.  We got another one today though.  My son was thrilled.