I didn't have to buy it. When I was looking for replacement lids for my sons sippy cups. I called playtex to find out if they sell the lids at a store near me, and they said no, not the lids, but they sell the valves. And I'm like my kids don't chew on the valve that's inside, they chew on the actual lid, and I was disaappointed that they don't sell the lids. Well guess what? Then the guy asked my how many sippy cups I had, and I said 3 of them, he said, he can mail me 3 lids, but they're all blue, and I'm like I don't have a problem with that. I got 3 lids for FREE.