Castelli Gabba Convertible Jacket: Castelli's Gabba Convertible Jacket manages to achieve a magical combination of water protection, superb breathability and a tailored fit. In partnership with Gore, Castelli developed their lightweight, 4-way stretch, waterproof Windstopper X-Lite Plus fabric specifically for this jacket. Plus, the Gabba is cut with a tight, aerodynamic fit, so you're fast and dry when others are wearing bulky, wet, sweaty jackets. Rounding out the Gabba are beneficial features like Nanoflex inserts under the arms for breathability, removable sleeves and a storm flap at the lower back to fend off wheel spray.