A set contains, 1 Black and 2 Green wedges.

They are made from a firm EVA foam.

The wedges are used to change the surface that your foot is articulating on. To create a situation where your foot has an opportunity to experience its natural articulations. With this comes the opportunity for change! Change requires something to be different from the current situation. That is what these wedges are there for...to create a new/different situation for your feet to move on so that they are able to experience their own natural articulations out of the shoes that you wear.