Monstrum Tactical TS01 Protective Sunglasses with Detachable Side Shields Polycarbonate lenses are both scratch and impact resistant, in compliance with Z87.1-2010 safety standards. Frame is crafted from lightweight TR-90 thermoplastic, more flexible and less susceptible to breaking than traditional plastic or wire frames. Flexible TR-90 arms with rubber coated, adjustable wire earpieces allow for a comfortable fit, for heads of all shapes and sizes Fully adjustable, detachable elastic head strap provides a secure fit while running, cycling, skiing, hunting, or other outdoor activities Detachable side shields provide added protection from wind, sun, glare, and debris.