Safety Sport Mirror The mirror is made of flat glass for an undistorted view of traffic behind the cyclist. Made in USA Mounts firmly because of the way the hollow rubber mounting block grips eyeglass bows and helmet visors. Virtually vibration-free due to its stiff mounting arm Mounts on fine wire bows, as long as they have a hinge long enough for the  long hollow rubber block to grip Mounting arm can be bent by the user for a custom fit (Instructions are printed on the display card.) Fully adjustable due to its a ball-and-socket assembly