Stay cool and comfortable on hot days with the Castelli Active Cooling Sleeveless Undershirt in Silver/Grey. This base layer is designed to actively cool you through evaporative cooling, using hydrophilic and hydrophobic yarns to hold moisture close to your skin while allowing airflow. The Polartec ® Delta fabric regulates drying to keep you cool, making it perfect for pairing with breathable jerseys like the Climber's or Superleggera. With a lightweight design and stylish sublimated overprint, this undershirt is a must-have for any cyclist looking to beat the heat.