The Keystone Vest is designed with the classic Colorado shoulder season ride in mind. Imagine your morning rollout in 30's, by lunchtime you're faced with temperatures hitting the 70's, and the entire course of the day you've encountered mountain ascents/descents that expose you to extremes at either end of that spectrum (and probably some rain too!). The Keystone is extremely effective at regulating your temperature while being light enough to wear through the entire effort (even though it will easily pack into a jersey pocket). And if you tend to run hot during exertion, we've included a reflective two-way zipper so you have venting options. Three full-size rear pockets and a fourth zippered security pocket allow you to stow everything you may need for an all-day ride.