Let them stay out a little longer in the Flurry boot. Features include water-and-wind resistant material, an easy barrel-lock adjustable lace, and thick rubber sole for traction. MIDSOLE: 2.5 mm bonded felt frost plug. INSULATION: Removable 6 mm washable recycled felt inner boot. OUTSOLE: Injection molded waterproof thermal rubber shell with multi-directional lug outsole for enhanced traction. UPPER: Durable water and wind resistant PU backed synthetic textile upper. Built in. gaiter with barrel lock closure system and fixed elastic instep strap.