100% SpeedCraft SL Sport Sunglasses are exactly like their big brother, the SpeedCraft, but pared down a bit to fit smaller faces. The nose piece doesn't wrap so far around the lens at the bottom, either. This design saves a few grams. The first thing you notice about 100% Speedcraft SL sunglasses is the single-lens design. Like moto goggles, the single lens is designed to provide the absolutely widest field of vision possible. There's no interference from an intrusive lens divider. The same is true of the top of the frame, which moves out of the way to increase your vertical field of vision. This is extremely important when you're in the riding position. It allows you to see what's ahead without tilting your head way back, which causes stiffness and pain (literally) in the neck.When you put the Speedcraft SL on your face, you'll notice that the lens sits a bit farther from your face than most sunglasses. This design forces a measured amount of air between the lens and your face to prevent fogging. The scoops on the temples augment this function, so your glasses won't fog, even during a slow grind up Mount Forever. Speaking of arduous climbs, 100% added a Megol hydrophilic nose pad to keep the sunglasses in place. In fact, the more you sweat, the better the glasses cling.Of course, you probably guessed that the lens is interchangeable. 100% was also kind enough to include an extra lens (low light) with the glasses, as well as an extra nosepiece, a micro-fiber bag, and a molded carrying case.