What Our Gearhead® 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™ 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.