The KEYSTONE lounge chair is inspired by the three basic elements of a roman bridge; the spanners, the elemental building blocks, and the keystone; completes the fundamental arch shape, which when inserted completes the fundamental arch shape. Originally made from concrete (back rest), rubber (keystone) and ceramics (sit surface). This version of the KEYSTONE chair is upholstered with textiles from the Kvadrat collection and produced by PLEASE WAIT to be SEATED.