Wearing a rain jacket on a damp day's ride won't do you much good if you're soggy under the shell and it's either flapping around or even catching so much wind that you feel like a parachute is attached to your back. With the Castelli Pocket Liner Jacket , you won?t have to choose anymore between ending up wet from your sweat or wet from the rain and you'll enjoy a sleek, body-hugging fit that won't slow you down.In close communication with the Cervelo Test Team first and then the Garmin-Cervelo team, Castelli refined the eVent fabric that it uses to such remarkable effect in the Pocket Liner Jacket. EVent is a waterproof fabric that keeps you dry in rainy conditions. However, unlike most waterproof materials that do not allow the body to breathe, the Pocket Liner Jacket's eVent membrane features millions of tiny pores that are small enough to block large water droplets but small enough to allow the water vapor that you're generating to escape. So next time you see David Millar in escape mode during a cold, rainy stage at the Giro, you'll know that he has a huge advantage over his competitors since he has the Pocket Liner Jacket in his arsenal of secret weapons. If he ? or you ? are soloing away from the pack in the rain, the Pocket Liner Jacket offers an additional advantage since it has been designed with a close, unobtrusive fit in mind. To give other rain jackets their due, outer layers of this sort usually have to be pretty roomy in order to fit over multiple layers, especially if you are using them in the winter and are wearing your heavy winter riding kit. The Pocket Liner Jacket fits over winter layers yet also doesn't bag and sag when you have only your jersey on underneath because Castelli incorporated pliss? stretch zones for a perfect fit without extra fabric.