These black 2XU Aero two-in-one shorts have a layered design with a stretch woven outer and PWX compression inner. Designed to support whilst keeping you cool, this pair has an elasticated waistband with internal drawcord, perforated inseam, side zip pocket, internal phone pocket and reflective logos and trims. As 'aero' is typically a reference to flight, we guess these 2XU shorts are conducive to experiencing the runner's high. That's what we'll be chasing in them anyway.