What Our Gearhead(R) Experts Are Saying: "This is one of those layers I never leave behind. It weighs almost nothing, blocks wind incredibly well, and breathes enough to wear while moving. I keep it clipped to my harness or buried in a running vest for quick protection on ridgelines or belays." We rely on the Aerofoil Hooded Jacket when speed, efficiency, and adaptability matter most. Built by Mountain Equipment for long alpine days, this ultralight wind shell offers serious protection from cooling winds while staying soft, stretchy, and comfortable directly against the skin. The EXOLITE 45 fabric cuts exposure without trapping heat, making it ideal for stop-start movement, sweaty climbs, and fast transitions. Its adjustable hood adds just enough coverage when conditions shift, and the entire jacket compresses down small enough to clip onto a harness or stash in a pocket. For trail runs, scrambles, or multipitch routes where weight is everything, the Aerofoil is a layer we always want within reach.