What Our Gearhead(R) Experts Are Saying:"I zipped this jacket up fully for a 40-degree climb, bracing for the usual overheating that comes with anything windproof front and back. Ten minutes into the effort, my core was working hard, and I still wasn't sweating through it, which never happens in a fully sealed jacket. The AirCore fabric let heat escape at the same rate I was producing it, so I stayed zipped the entire climb instead of stopping to vent."Rain rarely waits for a break in the ride, and the Perfetto 4 Jacket from Castelli is built for the exact moment it doesn't. The covered YKK zipper keeps water from working its way in at the one seam most jackets fail on, running top to bottom, so we can crack it open or seal it shut without ever exposing the track underneath. Road spray kicks up fast behind a wheel, and the longer drop tail with its reflective stripe covers that spray zone while keeping us visible to traffic as the sky darkens. Even the rear pockets carry drain holes, so a downpour that would normally leave gear sitting in a puddle just runs straight through instead. By the time the rain lets up, this jacket has already done the work of three separate pieces of gear.