TwinTrail – Women’s Medium-Warmth Double-Zip Fleece Base Layer

Meet the Beneunder Fleece Outdoor Base Layer — available in two warmth levels to adapt to different temperatures. Crafted from double-brushed fleece with high-stretch fibers, it keeps you warm without bulk and moves with you effortlessly. The fabric’s quick-dry technology wicks away sweat, while the slim fit layers easily under jackets or stands alone. Choose the Mid-Warmth version for 5°C to 15°C, or the High-Warmth version for -5°C to 5°C.

Highlights:

Double-brushed fleece traps heat, +1.9°C to +2.1°C warmth boost
Hollow-core fibers lock in warmth with 37.8%–44.1% better heat retention
Two warmth levels: Mid-Warmth (5°C–15°C) / High-Warmth (-5°C–5°C)
3.4× stretch with 360° mobility, no tightness
Sweat-wicking and quick-dry comfort for all-day wear
Lightweight slim fit, easy to layer without bulk

Double-Sided Fleece for Lasting Warmth

Double-sided brushed fleece with infrared heating boosts warmth by +2.1°C. Hollow-core fibers trap heat effectively, delivering 37.8% better insulation than standard fleece.

3.4× Stretch for Total Freedom

With 3.4× stretch and 94.5% rebound, the fabric adapts to every move. Stay flexible and unrestricted whether stretching, bending, or in active motion.

Quick-Dry Comfort — Stay Warm, Not Damp

Engineered with quick-dry technology, the fabric wicks sweat within 1 second and disperses moisture fast. Stay dry and warm without the clammy chill of sweat.

Dual-Zip Styling for Versatile Layering

The dual-zip design offers adjustable comfort and versatile styling. Wear it slim on its own or layer it easily without bulk—adaptable for any occasion.

Seamless Finish for Skin-Friendly Comfort

Seamless construction minimizes skin friction for a smooth, irritation-free feel—even during long wear.