Smartwool Men's Classic Thermal Merino Base Layer 1/4 Zip

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Men’s Classic Thermal Merino Base Layer 1/4 Zip

Built for performance in the coldest conditions, the Men’s Classic Thermal Merino Base Layer 1/4 Zip delivers warmth, comfort, and natural breathability when you need it most. Crafted from 100% responsibly sourced merino wool, this heavyweight base layer is one of the warmest in the range—perfect for skiing, hiking, winter running, or simply staying comfortable on frosty days outdoors.

The updated slim fit has been refined for better movement and a cleaner silhouette, while thoughtful details such as offset shoulder panels and flatlock seams reduce chafing when you’re wearing a pack or moving at pace. Merino’s natural ability to regulate body temperature, wick moisture, and resist odours makes this an essential layering piece for active use in cold weather.

A 25cm centre-front zip allows quick ventilation when needed, and the interlock knit construction provides a soft yet durable feel against the skin. Designed to work hard in harsh conditions, this base layer keeps you warm, dry, and comfortable mile after mile.

Details

• 100% responsibly sourced merino wool

• Heavyweight thermal base layer – ideal for cold weather

• Slim fit designed to follow the body’s contours

• Flatlock seams and offset shoulders to minimise chafing

• 25cm centre-front zip for easy ventilation

• Temperature regulating, breathable, and odour resistant

• Colour: Winter Moss Summit Soul