Do more with the Smartwool Intraknit Merino 200 1/4 Colorblock Zip Neck Top. Warm Merino Sport yarn is combined with the durability and fast dry times of polyester, to create a 1/4 zip midweight base layer that's prepared for the rivers of sweat a long day outside brings. Unzip and keep going with a men's specific mesh design made to increase breathability and movement in key areas. From high winter ascents to days chasing overenthusiastic children in the snow, the Smartwool Intraknit Merino 200 1/4 Colorblock Zip Neck Top is sweat tested and breathability approved.