An arch support is a type of orthopedic device used to provide support and cushioning for the feet. It is composed of several components, including a JAMB, PIER, SOLE, insole, ABUTMENT, and KEYSTONE. A JAMB is a vertical piece of material that forms the sides of an arch. A PIER is a support structure that helps to hold up an arch. The SOLE is the bottom part of the arch support, which provides cushioning and shock absorption. An insole is an insert that is placed inside the arch support to provide additional cushioning and support. An ABUTMENT is a support structure that helps to hold up an arch from the side. Finally, a KEYSTONE is a wedge-shaped piece of material that helps to hold up an arch from the top.