(Muck Boot Company) Superior quality and comfort. Made of 5mm CR-Foam top, a revolutionary material that acts as a “neutral medium” for conducting hot and cold external temperatures. CR-Foam is a super dense material, but extremely lightweight with outstanding insulating qualities to -10º. The CR-Foam Bootie forms a complete protective covering around the foot/ankle/calf for a comfortable, snug fit. Seams are vulcanized for a 100% waterproof boot, top to bottom. Multi-ribbed outsole provides excellent traction, comfort and shock absorption. Added toe protection with a wrap-up toe bumper.