We ordered this baby pool last summer for our 11-month-old. The pool is 38 1/2" in diameter. It inflates easily with an automatic pump. Inflating it is a little time consuming, because it has 3 different areas to blow up. Luckily, it held the air well and didn't need to be refilled very often. It is hard to clean though. The bottom is quilted and dirt gets in the crevices and is really hard to get out. I tried several time to get it really clean and finally gave up.
It was big enough for him to sit in and splash around, which was all we were looking for. It also had a cushioned bottom that was nice, especially since he was always trying to crawl out. We loved the fact that it had a canopy over half of it to block the sun. I just wish that the canopy had been a little taller. He could barely fit under last year and this year I know he'll be too tall. I was hoping it would last us 2 summers and as far as durability goes it would have. It's still in great shape. This summer we will either have to get a new pool or use this one without the canopy, because he's just too big for it. The age on the pool is 6 months and up, but I don't think many children will be able to use it with the canopy after 18 months.