Windshell designers are constantly searching for the optimal balance between breathability and protection, since too much of one often means too little of the other. The Agravic’s best-in-test recipe pairs air-permeable polyester (in the lower torso and upper back) with dense, wind-busting poly everywhere else. Even our sweatiest testers couldn’t swamp it out on 45°F trail runs in the High Sierra. The fabric blocks 25-mph wind, and the PFC-free DWR withstands drizzles (the more breathable panels wet out first). One chest pocket fits a smartphone, and the hood adjusts to fit a bare head or helmet.