The mornings and nights during your week long climbing trip to Vedauwoo can be chilly when you aren't sending it. Throw on the Arc'teryx Men's Nuclei Hooded Insulated Jacket to maximize your warmth without being weighed down. The Nuclei is stuffed with Coreloft insulation, which is made with highly crimped multi denier siliconized polyester yarn, making it lightweight, breathable, compressible and moisture resistant. You won't feel restricted when you wear the jacket thanks to its trim fit, gusseted underarms, and articulated cut. The Nuclei packs down to the size of a water bottle, so it takes up very little pack space and can be easily clipped to a harness.