Twice as flexible and durable as Titanium and three times more flexible and durable than stainless steel, FluidMetal redefines comfort. And after 8 hours on the water, your head will appreciate that. We've also added custom silicone nose pads and co-injected temple tips, ensuring that every frame fits perfectly and lasts longer than your boat. Optical-quality hinges stainless steel 3 barrel hinge. 8 base scratch and impact-resistant polarized polycarbonate lenses. 100% UVA/UVB protection. Worldwide lifetime warranty.