These Eco-friendly socks have been sustainably manufactured using our latest BCool fibre. Each sock is specifically constructed to the contour lines of the left and right foot, resulting in an anatomically perfect fit. When using a half size up running shoe, this heel and toe cushioned sock will assist with filling the space to prevent foot movement in the shoe. These running socks can also be used with true to size running shoes. Not only does this sock have excellent moisture-wicking properties, it too has a heel tab to comfort and prevent chafing keeping the sock in place.