The 1000 Mile sock is a sock within a sock. The inner layer stays with the foot while the outer layer moves with the shoe, thus eliminating friction on the skin & reducing wear & the risk of blisters. The unique mixture of fibres features the unique properties of new Wool Ultra: real wool that is up to 20% lighter than conventional wool. It is softer & less scratchy, with excellent wicking qualities & a natural ability to combat odours. Loop piled heel & sole panels, a flat toe seam & an arch brace help to provide a customised fit. This is a great sock for 3 season walking, hiking & trekking.