The Thermal Pro Vest is made with breathability in mind. Castelli admits it's not as warm as their other thermal vests, as intended by design. It provides warmth for your core but omits a membrane to avoid trapping moisture or excess body heat during hard efforts. This makes it ideal for high-intensity workouts in colder weather, or just staying warm on a cool-temperature recovery ride. It's a favorite training piece of Castelli's pro riders when it's not quite cold enough for a windproof vest. The vest uses Castelli's Warmer fabric throughout the garment to provide moderate insulation while preserving breathability and moisture management. During strenuous riding, the material wicks moisture to the outside of the garment to be evaporated, keeping you dry and comfortable for the entirety of your ride. It's a form-fitting piece with elastic grippers at the waist for a secure fit. Castelli finishes the vest with three rear storage pockets, and reflective accents on the back to improve your visibility to road users during twilight hours.