High Back Synchro Knee-Tilter Arti’s high-tech design provides enhanced back support and allows the spine to move and flex freely. The chair back articulates like a human spine allowing the chair back to reshape itself and mimic the user’s profile – automatically responding to body movements and sitting positions. The back rest is linked together by internal steel cables and highly graded steel springs, which play a vital role in ensuring maximum strength and flexibility. Arti's frame and horizontal flexible wings are made with tough, highly engineered grade plastics.