What Does the Castelli Pro Mesh M Short Sleeve Base Layer in Black Actually Do?

The Castelli Pro Mesh M Short Sleeve Base Layer in Black is the hot-weather base layer built around maximum ventilation rather than warmth, using an open mesh construction that sits against the skin to create an air gap between your body and your jersey. That air gap is the mechanism that makes a mesh base layer cooler than riding without one in high summer heat, allowing sweat to evaporate from the skin rather than saturating directly into the jersey and keeping the outer layer from clinging to your back during hard climbs. The mesh also provides a slight wicking assist that draws moisture away from the skin more aggressively than bare skin alone.

The body-mapped knit zones vary mesh density across the torso and shoulders, concentrating maximum airflow at the highest heat-generating areas and providing slightly more coverage at the sides where chafing from jersey seams would otherwise develop. The fit is snug enough to stay flat under a jersey without bunching, and the short sleeve length works under any road or gravel jersey from early spring through late fall. Machine washable in sizes XS through XL, made in Italy, the Pro Mesh M Short Sleeve Black is the base layer that makes your hottest rides noticeably better.