My kids love this product.I love it too.No more mess in my minivan & no more having to carry sippy cups where ever I go.I have 3 children,one is a baby so she doesn't use it.The others are 7 & 4
All I do is carry this cap & screw it onto a store bought drink & instant spill proof drink.I found it surfing the web here is the link.
http://www.sproutspout.com