I forgot to add, I am 5 ft 10in, so that is the reason I got a large one...I literally tried them on before I bought it...lol...but the one I have also has a heater to keep the water warm without adding more hot water...I was so disappointed when the dr. told me I could no longer use due to my new hip, I thought about having "indoor pool parties" in it...my family thought it was nuts!!!