More shredding, less shedding—that's what you'll be doing in the Marmot WarmCube™ Active Alt HB, our super light and breathable high performance puffer. This down jacket is designed to stop overheating in its (skin) tracks with stretchy, ultra breathable comfort from skin up to send down. Down insulation is isolated to your back and core, so you're arms and upper body have the freedom they need for throwing ice axes or the winning touchdown pass at the park. Internal temps are regulated by circulating air while you're moving and trapping heat inside down cubes when you stop. What does that mean? You won't get too hot on deep and steep skins or alpine scrambles when you'd typically be shedding layers, and you'll stay warm even when you're taking in the summit sights or catching your breath in the thick of the backcountry. Throw on a shell and you're ready to break trail from first light to last.