Wool is a staple of the DeFeet line. We source the highest grade wools on the planet. Combined with DeFeet construction, the result is the finest wool sock that you can buy. The DeFeet wool line is continually growing. This year we've added the Classico as well as a SpeeDe. Wool has attributes that can't be found in other fibers. DeFeet wool socks stay cooler in the heat because of the construction of the mesh. They stay warmer when they are wet and in cooler temperatures because of the amazing thermal properties of wool. Classico: The Classico sock delivers modern performance in a 'retro' looking design. Other than looks, there is nothing retro about the Classico. The finest Merino wools give the Classico true four season performance for cycling, running, nordic skiing, hiking, or just moving around town in a pair of clogs. Sizing: Small Women 6 8 Medium Men 7 9 Women 8.5 10.5 Large Men 9.5 11.5 Women 11 13 Extra Large Men 12.