It is designed to fit over thicker layers, so you can easily regulate temperature and it packs down small enough to fit in your jersey pocket for days when the weather changes fast.

Highly breathable waterproof 2.5 layer membrane
Extended tail for weather protection, but cut higher in the front for unrestricted pedaling
Elasticized cuffs and hem
Waterproof front zipper
BioVizTM reflective elements and high visibility colors 
Fully sealed seams

Body: 100% polyester woven twill
10k/30k 2.5 layer membrane with charcoal backing print
Fully seam sealed