Size guide
Foot lenght | 8.9-9.1 | 9.3-9.4 | 9.6-9.8 | 10.0-10.2 |
EU | 35-38 | 39-41 | 42-44 | 45-47 |
US | 4-5.5 | 6.5-8 | 8.5-10 | 11-12.5 |
UK | 3-5 | 6-7.5 | 8-9.5 | 10.5-12 |
Foot lenght | 22.5-23 | 23.5-24 | 24.5-25 | 25.5-26 |
EU | 35-36 | 37-38 | 39-40 | 41-42 |
US | 4.5-5.5 | 6-7 | 7.5-8 | 9-10 |
UK | 3-3.5 | 4.5-5.5 | 6-6.5 | 7.5-8 |



Description
For maximum protection and comfort in every step, Biotrek Heavy Duty combines Merino wool and Kapok fiber for exceptional thermal regulation, while Natex fiber, derived from castor seeds, keeps feet cool and dry during high-altitude adventures.
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Details
- Maximum protection and comfort in every sock
- High performance thanks to innovative bio-materials
- Fine Merino wool for warmth and breathability
- Kapok vegetable fiber, the lightest in nature
- Excellent thermoregulation even on cold days
- Natex fiber from castor seeds to neutralize odors
- Keeps feet dry during long hikes at high altitudes
- Item Code: SX1-S100338-B857
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Composition
- WOOL 33%
- POLYAMIDE 24%
- MODAL 21%
- POLYESTER 16%
- ELASTANE 3%
- KAPOK 3%
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Care Instructions
Machine wash at max 30 °C – mild processDo not bleachDo not tumble dryDo not ironDo not dry clean
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Shipping & Returns
Free shipping for orders over 150 CHF.
Duties and taxes included.
Free returns.
Features