HAG has designed and produced the Capisco chair which is based on the same sound ergonomic and anatomic principles as a horse's saddle. As with a saddle, Capisco has been designed to incorporate multiple changes of position while giving maximum comfort and support where it is most needed whatever the task being performed. The unique design of the Capisco's seat allows you to not only sit traditionally but the "waterfall" shaped edges open the angle of the hips thus naturally and correctly aligning the spine. The addition of a sliding seat adjusts the chair for users of different height to maximize back support. The back gives support in the normal way but the clever shape enables you to sit sideways, lean back with "elbow" support or even turn around and use it to give support to the chest for those really intricate tasks. The back adjusts simply and independently from the sitting position. The tension of the tilt can be adjusted to the users weight and locked into position by pushing the handle inwards. Sitting "back to front" and locking the tilt mechanism, the backrest gives support to the chest and the "wings" support the arms. The back has flexibility "sideways" following your body movements. Colors: Black, Burgundy, Navy, Dark Grey, Grey, Plum, Forest, Sky, Grape, Wine, Cherry, Cocoa, Teal. and sizes are as follows: Regular fits office desk heights of 26-32.5 inches. Medium: 30-37.75 inches. Tall: 37.7-43.3 inches.