The Aria Vest represents a new way forward for Castelli. Building the success of other pieces that have evolved quickly over the last few years, the Aria effectively blocks wind on the front without causing overheating and is now Castelli's lightest and most packable wind shell that fits close to body with a stretch breathable back. At 75 grams, while delivering the performance and fit you require, the Aria packs down small into it's own little pocket and there is no reason not to carry it any day the weather forecast is even remotely vague.
In reinterpreting the classic wind vest, the fit and function have been easy to understand and conceive, but what drives the success always comes from the textiles available, and the ability to produce the garment at reasonable price. By keeping the Aria under $100, with exceptional fit and performance, the design team at Castelli has met the reasonability threshold for most serious cyclists. The blocking, ultralight windproof woven microfiber up front is cut to match the stretch of the rear mesh, in conjunction with the anatomic limitation and ergonomic requirements of various cycling positions.
Keep in mind this vest is designed to completely block the wind on the front while allowing ample breathability on the back. The fabrics are so impossibly light that you'll be surprised at how much warmer you stay with this vest over your standard jersey. Most cyclists know vests to be effective, but never fit quite right. Most highly effective garments are built as a system, not as a collection of materials and details. You want you race jersey to fit and perform a specific way, hence the vest you wear over that jersey needs to conform and react in the same way. The Aria achieves this, superbly.