When your ultra run starts in the early morning light and ends once the sun starts to set, rely on the Julbo Aero Sunglasses with Spectron 3 CF lenses to keep your vision clear throughout the day. The Aero was designed with input from world class ultrarunners and weighs just under an ounce 26g per pair, and is fully padded at the nose and temple to deliver a comfortable fit and feel for the entirety of your race. Fogging is always a threat during endurance races, so Julbo put vents between the top of the lenses and frame to keep a constant supply of air passing through the lenses. The frame also allows for optimum ventilation with a design that enables air to circulate along the bottom, top, and sides of the lenses, leaving your vision free of fog, even as you push it to the top of a long and grueling climb. This version of the Aero comes with Julbo's Spectron 3 CF lenses, making them a solid, all purpose pair of shades for high output activities like running and mountain biking. Proposition 65 Warning for California Consumers: This product contains chemicals known to the State of California to cause cancer andor birth defects or other reproductive harm.