The Tifosi Podium has a frame made of Grilamid TR-90, a homopolyamide nylon characterized by an extremely high alternative bending strength, low density, and high resistance to chemical and UV damage. The Sunglasses have hydrophilic rubber ear and nose pieces for a comfortable, no-slip fit. Both the ear and nose pieces are adjustable for a customizable fit. Fototec lenses with variable tint technology adjust rapidly to changing light conditions for superior clarity and protection. In bright sun, microscopic photochromic particles embedded in the lens react to UV rays darkening the optics so you'll never squint. Then with cloud cover, the particles return to their previous state letting through more light. Tifosi Fototec lenses offer 100% protection against harmful UVA/UVB rays.