What Our Gearhead(R) Experts Are Saying:"I wore the Sense Aero GFX Cap on a midday trail run and the GridFlow fabric kept my head cool even as the sun climbed higher. It packed down small enough to stash in my vest when clouds rolled in later."Midsummer trail runs have a way of turning into a battle against the sun, and the Salomon Sense Aero GFX Cap is built for exactly that fight. We've reached for it on exposed ridgelines where shade disappears for miles, when heat radiates up off the trail as much as it beats down from above, and felt the brim do its job without adding a single ounce of bulk. The GridFlow fabric across the crown keeps air moving even when effort spikes, so sweat evaporates instead of pooling under the fabric. Reflective details catch headlamps and passing cars on early morning or late evening miles, and the whole cap folds down small enough to disappear into a pocket the moment you don't need it.