The only reason I'm giving it a 4 and not 5 star is that it's a little small for the seemingly intended purpose of being a swim bag. Now that might not be entirely fair because the specs do list the size, but due to the shape of this thing, it's not like the specs can be really spot on as it's not a simple rectangle. Still, this product works fine, and it's a nice choice for a little kid because it makes the backpack a little more fun.What we do with it is use it for our preschooler's swim class. It is adequate to fit a small towel, swim suit, goggles and perhaps another small item or two. This is tight when you fully seal it. But it works. Sometimes the kid does want to carry it on back and that looks really cute, but typically we're just slinging it over an arm to carry it along with other school items. It's great to keep the wet or damp swim class stuff well separated from everything else. It might not technically be wholly waterproof, but after a couple months of use now, we've never had anything that we put in there get anything else in contact with the bag wet.