The Smith Men's Attack MTB Performance Sunglasses are the ultimate companion for the trail and long adventures. These sunglasses feature Smith's MAG™ lens interchange system that enables you to quickly swap between the included bright-light and low-light ChromaPop lenses; improving visibility on the trail regardless of light conditions. For fog-free vision, the Attack MTB features a ventilation channel in the brow of the larger, maximum coverage lens. These details, combined with the secure fit of a two-position, hydrophilic nose pad and megol temples, make it the most complete trail riding eyewear piece ever created by Smith.