Simms Mens Merino Wool Thermal Midweight OTc Sock, Large, carbonMidweight Merino wool over-the-calf sock.Features of Simms Mens Merino Wool Thermal Midweight OTc Sock, Large, carbon STAY WARM: Merino wool over-the-calf socks are ideal year-round, including winter, because the fabric is excellent at thermal regulation by keeping you warm on cold day..