I just received a SALUS Nimbus pfd for my 4 year old. He's just shy of 40 lbs. I've been looking around and there really doesn't seem to be anything I liked out there for his weight range. So, on the recommendation of Carvedog, I went to the SALUS site, checked out their stuff, and ordered one. I really like this PFD. Since it's Canadian made, it doesn't notate on the vest what class it is (they' don't go by the USCG ratings up there apparently) but this is definitely much better than a class II pfd, I would rate it a class III. The fit is great, and he has really good mobility in it. This isn't a scaled down adults vest for little little kids - it seems well thought out. Float test in the hot tub coming up.