Worn once before my feet grew from pregnancy :/ From the listing at Xero Shoes (fits true to size but check out their website for size chart if you're unsure!): Waterproof, cozy, and warm! The Alpine keeps the wet out with a fully seam-sealed inner bootie and a waterproof membrane in the boot’s upper. The insulated polyester fleece lining keeps those piggies nice and warm. And a heat-reflective insole adds to the winter-friendly comfort. And, yes, you can remove the insole for an even more “barefoot” feeling. The Alpine has 200g of insulation so they should keep your feet warm no matter where your adventures take you. Lightweight and grippy A women’s 7 weighs just 12.2 ounces each, a luggy tread gives you sure-footed traction, and a flexible, non-elevated (zero-drop) sole lets your foot move naturally. Plus, the Alpine is made from 100% vegan-friendly materials. * Wintertime Natural Comfort * Insulated polyester fleece lining * Seam-sealed inner bootie and a waterproof membrane