The Aero is made for high intensity sports, designed for comfort and a wide range of movement—so you can focus on the task at hand. Need extra ventilation? Just unzip. Half zip for extra ventilation; Set-in sleeves for wide range of movement; flatlock seams to prevent chafing; feminine shaped hem Ultra lightweight, naturally odor resistant, breathable 90% merino wool, 10% nylon Machine wash. Dries fast in the shade, but do not tumble dry. Exact instructions on the care label.