You'll have to put in the work if you want to stand atop the box, and the Tifosi Podium XC Interchangeable Sunglasses are here to help with that. They have mirrored lenses that cut glare and athlete friendly features that keep them put when you're working up a sweat. But the best part is the assortment of lenses that they come with. Essentially, they enable you to swap them out to match the current light conditions. After all, it's easier to achieve your goals when you're able to see where you're going. Tifosi built the frames for the Podium XC out of Grilamid TR 90, which is a nylon blend. And, despite its fancy sounding name, the reasons for choosing this material were simple namely, it's tough and light. The toughness comes from a high bending strength, and it's bolstered by the material's resistance to breaking down under exposure to chemicals and UV light. Naturally, the light weight comes from the fact that it's a low density material. The frame also gets hydrophilic pads above the ear and at the bridge of the nose, which ensures that they'll stay put when you start sweating. Even better, the aforementioned ear pieces are easily adjustable to customize your fit. The lens employ's Tifosi's Clarion mirrored lens technology, which caters specifically to the needs of athletes. Along with the glare fighting mirrored finish, the Clarion lenses are given a hydrophobic coating that helps moisture roll off of the lens, instead of staying in place and obscuring your vision. The lens tints are consistent throughout, which saves your eyes from having to constantly readjust to an ever changing tint. And, if that's not enough, they're also compatible with Tifosi's RX adapter. This is an aftermarket lens that's available by prescription and snaps into place. As you'd expect, the lens holds the frame members in place, and it enables quick changes in order to suit differing light conditions.