Lose an extra pound this winter with Keen's Dakota Boot. Comfort rated to -25F the Dakota Boot features a patented waterproof technology that guarantees no water penetration while allowing moderate breathable comfort. This means that you enjoy a little more agility with fewer ounces locked in around your ankles. Unless you're opening a coffee shop in Antarctica it's probably safe to assume that the -25F comfort rated Primaloft insulation is ideal for most winter urban settings although you may need to find a -40F boot if you're faced with harsh survival situations. What you give up in those extra -15F comfort-rated degrees you gain in agility through snow mud and deep puddles.