What Our Gearhead(R) Experts Are Saying: "This is one of those jackets that does it all-durable enough for storm days, breathable enough for touring, and built with the kind of details you only notice once you're out there. The huge vents, removable powder skirt, and bomber fabric make it a shell you'll wear for seasons."When big days in the mountains call for dependable weather protection, we zip into the Flylow Quantum Pro Jacket. Built with a tough three-layer Surface shell, this jacket balances waterproofing and breathability so we can charge hard without overheating or getting soaked. Fully sealed seams keep moisture locked out, while a relaxed fit makes layering simple on cold midwinter missions. On the climb, 14-inch underarm vents dump heat in seconds, and on the descent, a helmet-compatible hood and removable powder skirt lock in warmth and coverage. With multiple pockets for stashing essentials and a construction built to last season after season, the Quantum Pro is our go-to shell for both storm laps and spring tours.