This thing is great, it's saved my girls a couple of times. I was right there and would have jumped in, but didn't have to!
Only thing is, it only lasts a couple of years, the chlorine eats into the seams on the sides and it falls apart.
My husband saw the same one at our pool supply place for $40, so you may want to check your local places first. We ordered the first one through the Humane Society, so I suppose some of that mark up is profits for them, not a bad thing