Monoflex is a new generation of transparent thermoformable plastic. The plastic has a unique cross-sectional design which enables the material to exert gentle and constant forces on teeth similar to self-ligating braces. The material fits accurately around interproximal spaces, attachments, and tooth contours, thus improving overall tooth movement and tracking. The superior mechanical properties of the material improve predictability with aligners due to minimal stress relaxation and longer working range.