Castelli Estremo 2 Shoe Covers

• Castelli’s warmest shoecover for extreme conditions
• Polartec® AirCore™ fabric for windproof water protection with maximum breathability
• Thermal lining to keep your feet warm
• Reflective details for high visibility
• YKK® AquaGuard® zipper
• High-durability material under foot

We set out to create our warmest bootie ever, which meant rethinking how booties are made. For the windproofing we went with Polartec® AirCore™ fleece-backed fabric, which also lets more moisture escape than any other windproof fabric. Then we added a second fleece layer, which is unrivaled in overall loft. The two layers are thick enough that we had to do a “wheel well” single-layer construction by the ball of the foot to prevent the fabric from rubbing on the crank. We made the bootie high for extra warmth and gave reasonable splash protection. We recommend pairing this with our Scorpion Logo 20 Thermal Sock for maximum warmth.