Made out of non-toxic silicone, the green parts are soft and pliable, while the stiffer blue parts are made from easily recycled polypropylene. This combination of materials creates a comfortable prosthesis that won’t leach nastiness into the environment.
Also very durable and resistant to most chemicals and acids, the fins will last a long time and won’t need constant replacing. According to the folks at Wired, they are not yet covered by insurance, so Stark has to come up with a plan to reduce costs. Even so, at roughly $350, the current model is a worthwhile investment.