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 Lightweight Boot is a boot height sock with minimal padding for close fitting protection from the elements. 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 Lightweight 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 Lightweight Boot Features Outer: 95% Nylon, 5% Elastane Inner: 45% Merino, 45% Polyester, 7.5% Nylon, 2.5% Elastane Membrane: 100% PU Boot length Close fitting Minimal padding Height:Mid Calf Bridgedale Stormsock Lightweight Boot