after following zip-fit video instructions more than once, i could not get the shell expansion by steam to work. customer service was non-existent. the pain was unbearable,even in the living room. i was ready to give them away.
then i read about the hot rice method for intuitions (which i also have and much prefer. and intuition has GREAT customer service )
i tried it on the zip fits and got a very nice fit around the ankle and achilles/heel area that was pain free. try it if you have had the same trouble as i did.fill a sock with rice and heat in microwave. then stuff into liner. after it warms the cork gel, put your foot in and give it time to remold with the shell closed around it.