Bolle Simmer Snow Goggles Flow-Tech Venting frame designed to reduce fogging and optimize the flow of air over the inside of the lens. Triple layer face foam for ultra soft micro-fleece is the only material on your face, backed by two layers of multi density foam for a firm soft fit. Forstay system allows for swinging outrigger to maintain perfect fit with helmets. Equalizer Vent technology uses a waterproof, breathable vent to eliminate any moisture. The result is a distortion free vision and no fogging at any altitude. Spherical Vented Lens. P80/Carbo Glas Lens