Gilets are a versatile bit of kit that will protect you from windy and showery weather. Fantastic when worn over a warm jersey in cooler weather and great as back up throughout the year. Used with arm warmers they allow you to carry on wearing short sleeve jerseys well into the cooler seasons.
Usually super light they'll scrunch up and fit into your jersey back pocket just fine. Some riders love the unrestricted freedom the gillet give your arms, while keeping your body warmer during cold rides of down steep descents.