Castelli Medio Long Sleeve Base Layer Enhance comfort on every cool-weather ride with the Castelli Medio Long Sleeve Base Layer , the ultimate mid-weight cycling base layer engineered for chilly and unpredictable conditions. Its medium insulation wraps you in just the right warmth when temperature hovers in single digits, but efficient moisture-management technology wicks sweat fast to keep your core dry and your tempo high. Made from a soft, polyester stretch fabric, it fits like a second skin, letting you slip easily under your favourite winter jersey without bulk or bunching. Beyond...