What Our Gearhead(R) Experts Are Saying:"I keep this in my pack year-round because it's light enough to forget about until I need it. It goes on fast when weather turns, blocks wind and rain better than expected for the weight, and never feels fragile when scrambling."We move through big days knowing weather can change without warning, and the Phantom Mountain Jacket is built for exactly that reality. From long approaches to exposed ridgelines, this shell from Rab stays packed small until clouds roll in, then delivers immediate protection without slowing the pace or weighing us down. The Pertex Shield Diamond Fuse fabric strikes a rare balance between durability and packability, standing up to brush, rock, and repeated use while remaining light enough to live in a side pocket. A streamlined hood with a reinforced peak adds coverage without bulk, articulated elbows keep movement natural on steep ascents, and secure cuffs and hem seal out weather while staying easy to adjust on the move.