Icebreaker Siren Hipkini Women's Thermal Underwear Briefs Navy Size S

The Icebreaker Siren Hipkini redefines everyday comfort with its Corespun™ fabric, wrapping merino wool fibers around a nylon core for durability that pure wool cannot match. Unlike synthetic briefs that trap heat and odor, this low-rise hipkini breathes naturally, stays fresh for days, and moves with you through workouts, travel, or long workdays. Its slim fit and flatlock seams vanish under clothing, while the ultralight 150 gsm fabric feels barely there against the skin.

Highlights

• 83% merino wool, 12% nylon, 5% Lycra blend for softness, stretch, and resilience
• Corespun™ technology: merino wrapped around nylon for enhanced durability
• Naturally odor-resistant and moisture-wicking—ideal for multi-day wear
• Low-rise, slim fit with flatlock seams to prevent chafing
• Ultralight 150 gsm fabric for all-season comfort
• Mulesing-free merino wool for ethical sourcing

In daily use

From morning commutes to evening workouts, the Siren Hipkini keeps you dry and comfortable. Merino wool regulates temperature, so you stay cool in summer and warm in winter. The low-rise cut sits smoothly under low-waisted pants, and the flatlock seams eliminate irritation during high-movement activities. Whether you're hiking, traveling, or simply navigating a busy day, this brief delivers reliable performance without bulk.

Full specifications

• Product type: Women's thermal underwear briefs
• Gender: Women's
• Size: S
• Colour: Midnight Navy
• Material composition: 83% Merino Wool, 12% Nylon, 5% Lycra
• Fabric type: Corespun™
• Fabric weight: 150 gsm (Ultralight)
• Fit: Slim Fit
• Waist style: Low-rise
• Seam construction: Flatlock seams
• Breathability: High
• Odor resistance: Natural (Merino Wool)
• Temperature regulation: Yes (Merino Wool)
• Moisture wicking: Yes
• Comfort features: Soft, itch-free
• Intended use: Everyday wear, active sports, travel, layering
• Care instructions: Machine wash cold, line dry in shade; do not tumble dry, bleach, or dry clean.
• Sustainability: Mulesing-free Merino wool

Final note

For those who demand performance without compromise, the Icebreaker Siren Hipkini is a wardrobe essential. Its blend of natural merino and technical fibers delivers comfort that lasts, making it a smart investment for active women.