Tifosi uses Grilamid TR-90 for the frame material. It is a homopolyamide nylon characterized by an extremely high alternative bending strength, low density, and high resistance to chemical and UV damage. Tifosi then incorporates a hydrophilic rubber ear and nose pieces for a no-slip fit. Adjustable ear and nose pieces for a customizable, comfortable fit. Vented lenses improve air circulation, prevent fogging. Lens Features: Smoke - a perfect lens for cycling, running, and active sports when the sun is high and the sky is a deep blue. The neutral tint of smoke lenses prevent color distortion. GT -( Golf/Tennis) these lenses are designed to improve your game. With a neutral color, the GT lens is great for full-sun and high contrast so you can quickly spot your ball in flight or help reduce fatigue while your are riding in bright conditions. EC (Extreme Contrast) - these lenses filter blue light to help pick up subtle breaks on the green as you plan your next putt or try to find your way through the trees on your favorite single track.</p - Color: Neon Green Sac, Part Number: