The Castelli Climbers 4.0 Short Sleeve Jersey is expertly designed for the hottest days when aerodynamics still matter. Utilizing CFD-based fabric placement and seam construction, this jersey ensures rapid cooling, lightweight performance, and optimal aero efficiency. The airflow shoulder construction and Flusso 3D fabric on the front provide exceptional breathability, while the StradaPro 3D back enhances ventilation. Elbow-length stretch sleeves with raw-cut edges offer a sleek look and feel, and the elastic waistband keeps the jersey in place, providing support for your pockets. With a YKK Vislon zipper for easy access, this jersey not only blocks over 90% of UV rays but also transitions seamlessly into a three-season option with a base layer, making it a versatile choice for summer rides.