Managing moisture is the key to staying comfortable in cold conditions, especially during big climbing, mountaineering and ski days, where stop-start activity challenges even the most refined layering systems. Long approaches, strenuous pitches, and never-ending belays make it hard to stay warm and dry.

Your base layer is the most important factor, helping your other clothing to work as effectively as possible. The Switch Base Zip-T is a highly specialised next-to-skin piece using our well-proven Octayarn fabric, this time with no face or lining fabric to ensure completely unrestricted moisture transfer and incredibly fast drying times.

Under the microscope, Octayarn is made from hollow, multidentate fibres, with each individual fibre having eight protruding cog-like ‘teeth’. This complex 3D structure increases surface area and traps warm air, improving warmth and moisture-wicking capability while reducing overall weight. Octayarn offers the thickness of an 80-denier fibre but for half the weight and considerably less bulk.

Combining perfectly with our highly breathable mid and outer layers like the Switch Pro Jacket, Switch Alpine Jacket and the Intra series, the Switch Base Zip-T makes hostile, cold conditions appreciably more comfortable, whether on a multi-day test piece or a local ski tour.