Our boys love the vests and they are great in the 6-8 ...
592775
Our boys love the vests and they are great in the 6-8 size.  The gloves are not really well made and don't fit well but overall the kids don't seem to mind.
4673239
This is a great suit for little boys. I bought it in size 7 and size 8 for the ring bearers in my wedding. My only complaint is that the pants don't quite match the size of the blazer. The pants seemed tight on both boys - one of which is a VERY skinny size 7, and the other is a chunky size 8. They will still work, but definitely won't be as comfortable as the boys would likely have preferred. They do look just as nice as other more expensive suits though.
1969109
These are great. I ordered them for my 2.5 year-old and 6 year-old sons about a 6 months ago and they've held up through multiple wears beautifully. I will say that my oldest probably won't get much more wear out of them, as they are *just* fitting his long torso now with the adjusters almost at the max length, so if you have an older kiddo with a long body you'd probably have better luck just ordering regular sized suspenders. They are great quality, however. The adjusters snap down well and stay put, and I've had zero problems with the clips so far. They are nice and tight. I actually bought these in turquoise for my boys as well, and we love them all.
271343
Love this item for my 4 and 6 year old boys, fits great and keeps them warm. Took off one star only because one of the elastic strings broke after one wash, but still functions well!
2735152
We like this a lot- the vest is adorable! It was smaller than we thought so won't get much wear from it.
3869792
My son is almost 8, but he is short for his age, so this fit him perfectly.  I bought him a size 8 for the vest, pants and jacket that goes with it.  FIts him perfect.
4438076
My son usually wears a 5/6 in most clothes.  He's 46" and 45 pounds.  I got these for a costume but wanted him to be able to wear them throughout the fall and winter.  I bought a 6 and they just fit with all the slack out of the straps.  He probably will be able to wear them for only a month longer.  They are a great quality and he LOVES them.  I really regret not getting a bigger size.
4574971
I bought the killer whale and the pink dolphin for my 3 and 4/5 year d. Both my kids are on the skinny side and the vests fit wonderfully. Some other reviewers said that the arm hole was bothersome, I think they haven't tightened the straps enough. I went with the sizing from the swimways website and measured my children with a measuring tape to get the perfect fit. It is excellently made and the kids love them so much they refuse to take them off which is nice so I don't have to worry about them taking  them off and jumping in a pool. The fin is perfect and is pliable enough that my kids wore them in the car, strapped in, and it wasn't bothering them. Overall really AWESOME and will buy again when my youngest gets big enough.
438650
Our son is that in between size of needing larger than 5T, but not quite a 5 boys. The size 4 worked great.
3646525
This is a great vest.  Two parts detach which is wonderful.  The only problem is is that the zipper has a tendency to get stuck which is very annoying
2450085
Bought this in Oct. 2014 for my then 11-year old son.  He is an average size boy, but the large was too small (short and tight) for him.  I am keeping this for my 2nd son who is 8.  He shall be able to wear it this year.
653033
Both a little big for an average 6 year old. Good thing is there are straps on the helmet and the vest so we could adjust them to fit him. HE LOVED it!!
2946176
I love the vest.  But I measured my 5 year old and his fit was a size 6.  so I ordered a 7.  but the 7 was a snug fit!  little disappointed in sizing but LOVED the vest!  Great quality!!
1854400
We have bought 6 of these life vest. We have three 65lb labs, one 55lb, one 80 lb, & one 95 lb. The XL fit our 55 lb and 65 lb labs great. They keep them afloat very well and were comfortable for them to sit and lay in the Canoe. The two bigger labs at 80lbs and 95 lbs we got the 2XL. They fit around the belly of our 95 lb lab really good. It was a little loose around the belly on the 80 lb lab but still ok. But the neck strap on the 95 Lbs and the 80 lb Lab was way to big. I had to move the hook and the velcro. After I did they fit just right and did keep them afloat very well. The pictures are before I fixed them.

The green one was not perfectly smooth it was almost like the floating inside was bigger than the material and did not fit good so it was lumpy but after it got wet that seemed to fix it's self some what and it keep him a float. I have had some that are better fitting but I did not like the material it was made from so...
2488765
My dogs love to swim in the pool. The problem was that they couldn't just stand there when they get tired of swimming like we can, so they would come to us to hold them while they rested. With these vests on they don't tire as quickly, so they can swim a lot longer. Despite the vest being used in the pool many times, which includes the dogs jumping off the platform of the ladder, the zippers have not opened at all, which some other reviewer had a problem with. The measurements are true to size and they are easy to put on and take off. I can't comment on how they would be for boating and ocean swimming, because we don't do that, but for pools they are great. You can see pictures of my girls wearing the vests if you click on the other pictures link above.
2687750
We ordered this along with a green Chris Power Suit after seeing Wild Kratts Live. The kids love them, while I love that they can pretend in a positive and proactive (save the animals!) way. Each suit comes with 2 (different) power discs and the vests fit great. They have adjustable velcro along one side of the ribcage and one shoulder, which helps immensely. The only reason why I gave this product (and, thus, the Chris suit) 4 stars was because the gloves are sized to a 2yr old. My 4.5yr old (42" tall and slender) and 6yr old (49" tall and very slender) cannot wear them at all comfortably.... A real miss for this design and a real drag, considering that's half of the outfit. Otherwise, I'm sure they'll be activating creature powers whenever possible!
2092953
My son loved the vest ! He usually wears a small men's but we ordered a medium and it fit great!