What else you might want to know....
How do I convert the Sippy of Steel into the Thinkster of Steel?
One of the great things about the Thinkbaby Thinker System is that you can convert the baby bottles into Sippy Cups and then on to the final stage - the straw bottle (Thinkster).
Converting the baby bottle into The Sippy: Remove the baby bottle nipple and replace with the Sippy Cup spout. Then place the Sippy Cup handles around the top of the baby bottle and push down over the neck of the bottle. Tighten the collar with spout around the neck of the bottle and…presto! You have our award winning Sippy Cup!!!
Converting The Sippy Cup into The Thinkster: Take collar off of baby bottle (along with spout) and screw on the Thinkster top. Ta-da! The Thinkster!
And congrats-- you not only saved the landfills, but you also saved yourself money by lengthening the useful life of your bottle.