I tried the Phoenix ventilator shortly after I got out of my cast from major ankle surgery. They fit perfectly, the size was spit on. It felt like a very comfortable glove enclosing my foot, and my opposite foot, which had developed plantar fasciitis, was virtually pain free thanks to the air cushion heel. The sole grips like glue, so I can actually go up and down stairs with reduced effort. I'm grateful for the people at Boot World who showed the Phoenix to me.