0mm. We added a waterproof GORE-TEX upper to one our top-selling road shoes. It’s the classic Altra feel with a soft midsole, now designed to keep your feet dry on rainy days. GORE-TEX Invisible Fit is a lightweight, waterproof upper backed by the GORE-TEX GUARANTEED TO KEEP YOU DRY™ promise. With a heel collar that molds to your foot, zero drop, and plenty of room to help your toes move more freely with a secure midfoot, you’ve got the uncommon comfort you need to slay those road miles. Underfoot, you’ve got a redesigned midsole foam that’s lightweight, plush, and ready to perform. Stay dry. Stay comfortable. Stay Out There™!