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. Adjustable ear pieces for a customizable, comfortable fit.Tifosi Optics Interchangeable sunglasses feature decentered shatterproof polycarbonate lenses to virtually eliminate distortion, give sharp peripheral vision, and offer 100% protection from harmful UVA/UVB rays, bugs, rocks, or whatever comes your way. Lens installation/removal is fast and easy.