Chase the horizon with the Costa 6S9131 Mainsail XL sunglasses, crafted for coastal explorers and designed to perform in demanding environments. These square frames, made from durable nylon and propionate, deliver a sleek, modern look with sharp angles and strong lines. Finished in grey with blue mirrored polarized lenses, they cut glare and enhance contrast for crystal-clear vision, even in intense light. Advanced micro side shields and hooding minimize light leaks and protect against the elements, while vented nose pads keep fogging at bay during active pursuits. Complete with retainer-ready temple tips, these Costa sunglasses are built for watermen who demand bold functionality on every adventure. See what's out there with unmatched style and innovation.