My 12 year old and 10 year old love it!
I have owned many a shaker bottle in the past, but this one takes the cake - er, protein (this is for healthy things, after all). The fact that the shaker ball is attached to the middle rod is such a helpful feature. My kids no longer can take it and use it as a bowling ball, which is a plus. Each piece of the shaker is easy to disassemble and clean, making this the best shaker I have ever owned.