Bridgedale Storm Sock is a 100% waterproof breathable PU membrane lined sock for activities where your footwear may not be providing the level of warmth and waterproofing that you need. The Stormsock Midweight Boot is a boot height sock with a resilient cushioned footbed, heel and ankle. It is composed of 3 layers. The outer layer is made from Nylon and elastane which provides a durable protective layer for the waterproof PU membrane. The middle layer is the PU waterproof breathable layer. The lining is made from a Merino Wool and Polyester blend which is durable, wicking and benefits from Merino Wool's natural anti-bacterial and anti-odour properties. The Stormsock Midweight Boot is ideal for cycling, mountain biking and running in cold and wet conditions when your footwear is designed for function rather than protection from the elements. Bridgedale Stormsock Midweight Boot Features Outer: 95% Nylon, 5% Elastane Inner: 54% Merino, 36% Polyester, 7.5% Nylon, 2.5% Elastane Membrane: 100% PU Boot length Well cushioned footbed, heel and ankle Zonal padding system Height:Mid Calf Bridgedale Stormsock Midweight Boot