Stopper hinge to prevent the temple from scratching the lens</br>A contoured fitted bridge</br>Case included</br></br>Product Description</br></br>The CK4227S is made of zyl a flexible plastic and include polycarbonate lenses that are lightweight?? impact-resistant and have scratch resistant coating. They also feature a contoured fitted bridge and a stopper hinge that prevents the temple tip from touching the back side of the lens preventing scratching on sunglasses.</br><br/>http://www.amazon.com/gp/product/B00G32QYN6