I have been a faithful customer to Gerber. After trying several sippy cups when Timothy was 1, this is the one I landed on and found it very satisfactory. When Samantha was born, it became even more convenient because the pink and green come in the same pack. It's just a rule now that the green ones are Timothy's and the pink one's are Sam's. Unfortunately, just like pairs of socks in the dryer, the spill-proof valves seem to go missing! After no luck finding the replacement valves at Walmart or Target, I decided to write Gerber and ask where I could find them before I start searching all over San Diego. Within a day they responded with a list of about 10 stores that supply the valves (all grocery stores). I was quite pleased with that information alone, but then the very last sentence of the letter said, "We would be happy to send you a complimentary pack until you are able to locate these stores." That was about 4 days ago, and they arrived in the mail today! I am a very happy consumer.