Is it a jersey? Is it a jacket? It's a Jack-sey! The Jack-sey is perfect for the in-between temperatures when you aren't sure if you need a jacket or if just a jersey, vest, and warmers will do. It offers all the protection you need, with GORE-TEX INFINIUM™ WINDSTOPPER® lining on the front. The FLY SL shell outer layer has a water-repellent finish to keep you dry, and the amazingly light CLIMA SL insulation is just enough to keep the chill away. The low/no collar sits close so that no unwanted air goes down inside, but not having a collar helps with temperature regulation. When you can't decide what to wear, you reach for the Jack-sey.