I had these for my kids - didn't really like them though. If I remember correctly, their purpose is to just assist the child in staying afloat - a product to help them master swimming, not to save them if they don't know how to swim. They call them a teaching tool.

Your warning to other parents is a good one though. I can see where someone could easily get a false sense of security if they didn't really know much about this product.

Thank goodness your daughter is ok.