Manufacturer page.

Mirra 2 moves with you, at one with your body. When you sit, Mirra 2 adapts to you instantly. Shift, and the Butterfly Back™ and AireWeave™ 2 suspension seat dynamically support even your slightest movements. Recline, and the reinvented Harmonic™ tilt provides a smooth, balanced feel. An athletic attitude and plenty of opportunities for personalization define Mirra 2’s lean, sophisticated design. The emphasis on performance is visible. The Butterfly Back, a hybrid structure that merges a fabric layer with polymer veins, makes the chair more responsive, while bringing visual lightness to any environment.