The Men's Aero Race 4. 1 Solid Full-Zip Jersey from Castelli takes the cut and materials used in the standard AR 4. 1 and dyes the fabric, rather than the usual sublimation print on fabric, to give it deeper and more saturated colors. Typically, high heat and pressure from sublimation printing produces a shiny look to the material while this new technique that Castelli employs results in a richer look. What doesn't change is the great fit, excellent comfort, wonderful moisture management and of course, superior aero performance befitting its racing pedigree. Castelli claims this jersey saves approximately 12 watts at 40 km/h compared to a standard race-fit jersey. This comes in part from the Velocity dimpled fabric on the front and shoulders that not only improves the airflow but also helps increase wicking for a dryer you and a quicker drying jersey. Under the arms, Nervato fabric further improves aerodynamics, while the mesh raw-edge armholes place a gentle hold on your biceps and triceps. When the heat builds up, a full-length YKK Vislon zipper offers relief and when zipping back up, the neck protector ensures nothing gets pinched and there's no rubbing or irritation. On the back, the usual 3 pocket arrangement hauls snacks and tubes, while a zippered pocket keeps essentials safe. Just below that, the silicone gripper elastic at the waist prevents the jersey from migrating over the course of the ride. Finally, reflective heat-transfer viz strips add a touch of safety in low-light conditions.