Coming in at less than a pound, the Rab Xenon X Hooded Insulated Jacket features ultralight yet warm PrimaLoft Gold insulation, a packable design, and a helmet-compatible hood to give you the extra protection you need for alpine excursions. PrimaLoft Gold is comparable to down in terms of warmth and weight, but unlike down, it won't lose its insulating properties at the first sign of moisture. Pertex Quantum is light, yet durable to withstand frequent brushes with rocks, and the slim makes it easy to layer this piece under a technical shell in winter. Elastic cuffs help you seal this jacket around your gloves to keep out snow, and a waist drawcord does the same thing lower down. Rab designed the YKK front zipper to go up to your nose, so you can really seal out the weather when things get nasty. Plus, this whole insulated jacket stuffs into its own chest pocket for easy storage when the clouds clear and the wind dies down a bit. The Xenon X Hooded Jacket is there when you need it, and you won't notice the weight when it's just chillin' in your pack.