The material that my medical device uses is flexible plastic, metal, and velcro. The flexible plastic is used for the main piece (which is where you put in your leg) so that you can still bend your leg with the knee brace on and I would also like it to be thin so that you can tighten it around your leg. The reason I have metal is for the little rectangles at the top and bottom (that’s where the velcro goes through). Lastly, I have the velcro so that you can make the knee brace your size. The physical description of my medical device is that it has 4 different places to put the velcro. How you put the velcro in is you slide it through the top and bottom slits and strap it as tight as you need to be. I also have flexible plastic so that you can still bend their knee, and the metal is because I know it will stay in place. The use for it on Mars is so that the astronauts can still jump up and down on Mars and not have their knee hurt every time they land (This is also used on earth).