Bought a swim zip for my 18 mo daughter and it exceeded expectations-especially for the price! Super easy to put on suit, much better than the one piece zip up we used last year, and great quality. She has worn it 4-5 days a week the last couple weeks. It dries overnight, goes well in washing machine, and is super cute. Highly recommend. My daughter is 25 lbs, not too tall, and 18-24 makes fits well. I use a swim diaper and swim bottoms stay up well over the diaper. Would purchase again definitely!