The Arc'teryx Kyanite Baselayer Bottom Women's are heavyweight synthetic base layer bottoms engineered to deliver warmth and mobility in cold conditions. Designed for use as a next-to-skin layer during alpine travel, winter hiking, ski tours, and low-output cold-weather activity, these bottoms combine insulation with stretch and breathability to manage moisture while keeping the wearer comfortable. Constructed from Polartec® Power Stretch® Pro fabric, the Kyanite bottoms pair a durable nylon outer face with a soft, brushed interior that traps heat and feels comfortable against the skin. This four-way stretch material supports unrestricted movement on the go and conforms to dynamic body motion whether you’re ascending, glissading, or pausing for rest. The material is moisture-wicking and air-permeable, allowing excess heat and perspiration to escape during periods of higher output while still maintaining thermal efficiency when activity slows. The trim, next-to-skin fit enhances thermo-regulation and makes these bottoms ideal for layering under shells, ski pants, or insulated shells without bulky feel. A zippered thigh pocket offers practical storage for small essentials such as keys or a phone while moving, and the high-waisted design helps retain warmth around the core. These features, along with the fabric’s quick-dry properties, make the Kyanite bottoms versatile for a range of winter objectives where cold, mixed-output conditions are expected.

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