No excuse to get stuck without an extra layer, the Arc'teryx Solo Jacket for Men, weighting in at just 14oz, has a built in stuff sack and is so compressible you can throw in your jacket pocket. Built with Arcteryx single layer TermaTek laminated insulation, it is extremely warm for its weight, hydrophobic breathable, making it a great summit jacket, midlayer, or base camp pullover.
Arc'teryx solo jacket
This jacket is warm, very wind and water resistant, and tough enough to wear as an outer layer on nearly any pursuit (keep your usual outer layer when climbing sharp rock though). The outer fabric is very loud though - think about crushing up a tarp every time you move. Runs a little short in the front but full length in the back. A little annoying when climbing as it comes well above belt line every time I extend an arm.
