A performance thin weight, waterproof mid-length sock designed specifically for MTB (Mountain Biking ) for conditions where minimal insulation & maximum breathability are required. Featuring our unique Hydrostop technology which gives you a much more secure fit between your leg & the top of the sock, meaning the chance of water ingress through the top is massively reduced. Constructed with our proprietary Stretchdry waterproof, breathable & windproof technology Our lightest waterproof sock, ideal for warm, wet days Silicone free elasticated taping provides a secure fit at the cufff reducing the chance of water ingress allowing you to stay out for longer Merino wool lining for moisture control & comfort Elasticated ankle & insteps offer support & a comfortable fit Hydrostop Usage Guide Seal Skinz Hydrostop technology creates a seal between the sock cuff & skin, helping to reduce the amount of water from running down the leg & into the sock. Due to this close bond between sock cuff & skin, we recommend that Hydrostop socks are only used outdoors & not for a prolonged period of time. Incorrect or prolonged use can result in excessive rubbing against the skin & may in a very small minority of cases cause minor skin irritation. The Hydrostop seal material has been fully tested to EN ISO 10993-5: 2009 & is OEKOTEX compliant.