Tifosi Altar, Crystal Purple Sunglasses are constructed of Grilamid TR-90, a homopolyamide nylon, which allows for tremendous bending strength and has high resistance to UV and chemical damage. Additional Features: Hydrophilic rubber nose piece & ear pieces, which are adjustable, to enhance the comfort and no-slip fit. Lenses: Included with this sturdy, low-density frame are AC Red, Clear, and Smoke Lenses. Weight: 34 grams. Fit: Small to Large.