O'Neill Toddler Reactor-2 2mm Back Zip Full Wetsuit for Kids - Warm & Flexible Neoprene Swimsuit for Surfing, Swimming & Water Sports

Have only used once, but it is really well made and I have a degree in fashion design. It does smell a little like marijuana, but I am sure that will go away after a few uses. It kept my son a lot warmer in the beginning, but once the water had plenty of time to drop his body temperature he got cold again. But is I kept him moving, jumping, etc. he was happy. Also I figured out that I can hold him by grabbing a chunk of the zipper section on the back with my hand and then he could swim with his arms freely instead of trying to cling to me and he liked this. The swim class is about 50 min and I'd say he didn't start getting cold until 3/4 of the way through. My son is about 36" and weighs 26 lbs. size 1 fits him perfectly, not too tight, just a little bit of wiggle room.