Castelli developed the Climbers 3.0 SL Jersey in conjunction with Team Ineos for the rigors of pro racing in hot weather and in the high mountains. Racing in the Alps in July is for a select few, but the products that come out of that experience are absolutely amazing for the rest of us. The 3.0 SL is extremely lightweight and features open fabrics for additional airflow and quick drying. By using the same patterning as the Aero Race Jersey, the designers made sure you get maximum aerodynamics as well. Even if you don't race over the highest peak roads this summer, you'll love the soft stretch and great fit of this jersey, and you'll appreciate how it keeps you cool on the hottest days. Maybe you'll even do like the pro riders do and use it on wet days because it doesn't soak up any moisture. And you'll certainly appreciate that the fabric on the back blocks more than 90 percent of UV rays.

Functionally, the StradaPro 3D and Flusso 3D fabrics serve to lift a high percentage of the jersey off your skin surface. Moisture is released freely from the skin, and not held in the jersey, keeping you cooler and drier as you exceed threshold in your maximum efforts. The performance grades this piece out as Rosso Corsa, the pinnacle of Castelli's line. The elbow-length stretch sleeves with raw-cut edge, relying on the fabric's stretch for ideal hold. Fit-wise this is a pure pro-style, race cut performance piece. That may limit the options of those larger body cyclists who would love the benefits. Even most but the fittest, small structure pro's may find themselves sizing up if they are on the cusp. The fact is the Climber's 3.0 SL Jersey must conform to the body to be maximally effective.

Castelli has crafted a unique garment with all the technological credentials one could dream up, but as with all Castelli garments, excellence is also executed in all the "lesser" details. A full length YKK zipper ensures easy on-off, and more air flow if needed. One challenge to such a lightweight and porous garment is sun and ultraviolet protection. The StradaPro 3D panel on the rear blocks more than 90% of UV rays on your back The drop tail set-up stabilizes the rear pocket system, and the hem holds the whole assembly down for zero movement an incredibly sleek bib to jersey transition.