Pearl Izumi's Women's P.R.O. Aero Jacket is made of their stretchy P.R.O. Softshell Lite fabric to protect you from the weather and not cause wind drag to slow you down. Plus it has Pearl's Direct-Vent mesh panels for excellent breathability, a contoured collar and sleeves for a fine fit and feel, and reflective accents for safety. It packs small too so you can carry it in your pocket.