Meet the layer that quietly becomes your go-to for just about everything. The Aenergy Light ML Half Zip is built for people who chase sunrises on summer ridgelines and still find themselves skinning uphill in February. It threads that sweet spot between warmth and breathability, using a featherlight build that never bogs you down, even when you’re moving hard.

Mammut uses Polartec® Power Grid™—a clever knit that traps heat in its geometric pattern while letting excess moisture escape fast. That means you stay warm without ever feeling swampy, whether you’re grinding up a skintrack or powering through a trail run. A deep half-zip lets you dump heat on the fly, and the laminated zip pocket holds the small essentials you always need close.

Built with recycled fibers and certified to both bluesign® and Fair Wear standards, this piece delivers top-tier performance without skimping on responsibility. Streamlined, stretchy, and ridiculously versatile, it’s the layer you’ll reach for more often than you expect.

FEATURES

• Polartec® Power Grid™ fleece for warmth with excellent moisture management

• Recycled polyester content for reduced environmental impact

• Long half-zip for easy venting and on/off

• Bonded chest pocket with zipper for secure storage

• Flatlock seams for smooth, chafe-free comfort

• Ultra-light design suitable for year-round layering

• Responsibly produced with bluesign® and Fair Wear certifications

SPECIFICATIONS

• Fit: Athletic

• Weight: 181 g

• Main Material: 90% Polyester (recycled), 1% Polyester, 9% Spandex

• Insert: 83% Polyamide, 17% Spandex

• Insert 2: 100% Polyester (recycled)

• Best For: Hiking, mountaineering, ski touring, trail running