I think josh wore vests with poppers til around age 2, Then when he started spending more time nappyless i switched to the grown up vests as they were easier to manage daily potty usage for him. He still wears a vest everyday now, I t really annoys me how children don't put a vest on their child, I don't put josh in one when its really warm but we dont get many of those days. My sis in law stopped buying vests when her kids got 12mth & they never wear one now, they are age 6, 4 & 15 mth ish.