What Our Gearhead(R) Experts Are Saying:"I use this when a tee feels too light but a midlayer would be overkill. It's incredibly breathable, dries fast, and stays comfortable even when I'm pushing hard. The wrap-style hood and thumbloops add just enough coverage for cool starts and exposed sections."On crisp mornings when we're moving fast and warming up quickly, the Sonic Hoodie is the layer we reach for. Built by Rab as a technical baselayer with added coverage, it bridges the gap between a short-sleeve top and a full midlayer for high-output mountain days. The Motiv(TM) Aero fabric uses bulk yarn technology to wick sweat efficiently and regulate temperature as effort levels rise. A close-fitting wrap-style hood offers light protection without trapping heat, while underarm gussets and excellent articulation allow unrestricted movement on climbs and scrambles. With low-bulk seams, hidden thumbloops, and an odor-control treatment for multi-day use, this is a breathable, do-it-all baselayer we rely on for fast hikes, mountain runs, and demanding ascents.