The lightweight Castelli Aria Vest will protect your core from chilly wind. Made with an ultralight windproof woven microfiber front, wind will not penetrate the vest while the mesh at the sides allows air to circulate so you don’t overheat. The fabric is stretchy, so it conforms to the shape of your Castelli jersey. The Aria Vest fits like a second skin so no vest flaps in the wind and no wind penetrates to affect your comfort zone. A rear pocket with reflective piping provides food storage and visibility when it’s overcast. When you need to store the vest, it folds up neatly into a small packet that you can easily store in your rear jersey pocket.