The original AireatorR Double Cuff is built by cyclists for cyclists. Born in 1992, the AireatorR is the first product that launched DeFeetR and today its still the workhorse of the DeFeetR line. The AireatorR is the undisputed, original airflow design and first sock with a open mesh weave instep hence the name. It was also the first design sock that was customized with a logo, colors, and text. Before the AireatorR, that simply wasn't done. It has been worn to victory in nearly every International cycle race. The AireatorR still leads in lightweight, durability, moisture wicking and air permeability. The original AireatorR features a 'Double Cuff' which provides additional compression in the ankle zone. It's what we call 'Stay Fast', meaning, it will not slip from the moment you pull them on, to the end of a long day in the saddle. The double cuff also gives ample ankle coverage and feels slightly tighter compared to our single layer cuff design. Made from COOLMAXR EcoMade, the eco friendly polyester that comes from recycled plastic bottles. 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.