DESCRIPTION:An extremely lightweight, compact, close-fitting windproof shell with breathable stretch panels that lets you wear your favorite Castelli garments in wider temperature ranges. The Aria Shell jacket is really quite different from your old loose-fitting jacket that either didn't protect you or didn't breathe. This jacket is an incredibly lightweight layer that acts as a wind barrier on the front of your body and also guarantees great breathability thanks to the mesh side panels. But what you'll greatly appreciate are its stretch panels on the sides and back of the sleeves so this jacket hugs your figure like a second skinDETAILS : Ultra-light, windproof woven microfiber on front Stretch mesh strips on sides and back of sleeves to keep fabric from flapping in the wind Extremely compact when folded Rear pocket YKK® Vislon® zipper Reflective piping Weight:125 g Temperature:10°C - 18°C / 50°F - 65°F Fit: Comfortable Insulation: 1/5 Waterproofing: 2/5 Wind resistance: 4/5 Breathability: 5/5 Lightweight: 5/5