The Helium II jacket was designed to protect against storms when on an exposed trail. At only 180 grams, this rain shell packs into its own interior pockets and becomes the size of an apple. It's made of Pertex Shield+ 2.5 layers, a waterproof, super-breathable fabric that has an amazingly durable 30-denier exterior. The seams of this rain shell are also fully taped for maximum waterproofing.
 
Features: 
Pertex® Shield+ 2.5L
Waterproof, breathable with taped seams
Adjustable hood
YKK® AquaGuard® front zipper
Napoleon zippered pocket
Interior pocket doubles as a storage bag
Elasticated cuffs
Drawstring hem