This joint goes with the Iron Man Mark IV / VI boot. You will need to purchase two of these to make a complete boot. Other parts you will need to order would be the Iron Man Boot Heel and Iron Man Boot Toe. Designed to print at a thickness of .72mm, (minimum for Strong Flexible Plastic is .7mm). This saves on printing costs and WILL need some reinforcement on your end. Most people use fiberglass resin.