Designed for colder conditions, the Siren 4 Thermo Lace WP delivers warmth, waterproof protection, and a women's-specific fit. Featuring Primaloft(R) insulation, faux fur lining, and Vibram(R) Icetrek traction, it's built to handle snowy sidewalks and chilly trail days. Lightweight FloatPro(TM) foam adds lasting comfort without the bulk of traditional winter boots. Design: Waterproof membrane seals out water and lets moisture escape Waterproof coated leather upper Waterproof pig suede leather upper Medial zipper for easy on and off 100% recycled laces Bellows tongue keeps out debris TPU waterproof shell for additional protection Faux fur lining 200 grams PrimaLoft(R) Gold Eco Series synthetic insulation In-Shoe Comfort: FLOATPRO FOAM(TM) footbed for enhanced cushioning and energy return 100% recycled mesh footbed cover FloatPro(TM) foam midsole with exceptional energy return and enduring comfort. Durability & Traction: Vibram(R) Icetrek outsole designed to provide the improved grip on very cold, icy, or snowy surfaces