What Our Gearhead(R) Experts Are Saying:"This vest punches above its weight on long climbs and ski tours-it warms my core without overheating. I wear it over a base layer or under a shell depending on the day, and it disappears into my pack when I don't need it."The Rime Air IN Hybrid Vest is one of those layers we bring on every mission, from windy ridgelines to cool morning approaches. Mammut designed this vest with a hybrid construction that balances warmth, mobility, and breathability, all in an ultralight package that takes up nearly no space in our pack. Mammut's LOOPSINSULATION(TM) offers reliable warmth even when damp, while stretch paneling provides enhanced airflow and unencumbered motion. The wind- and water-repellent shell features a PFC-free DWR, and the vest stashes neatly into its own pocket when the sun rises or our output heats up. Two harness-compatible zippered pockets keep energy bars or gloves close at hand, rounding out a minimalist layer that's big on function.