When it's hot, the fibres of the Merino Wool will absorb your body's moisture vapours and evaporate them outside of the fabric - keeping you nice and cool so that you don't bake in the heat. When it's cold, these moisture vapours will condense inside the fibre, giving off heat and keeping you nice and warm. Merino wool and polyester blend - for a soft to touch and warm layer with the resilience to lastClassic long sleeve and crew neck - for a comfortable fit with full coverageFabric: 50% Merino Wool, 50% PolyesterColour: Black