skip to main content

Mens Heavyweight Merino Activewear Zelios Thermal Bottoms - Charcoal


By Paul James Knitwear


Product Details

Designed to eliminate all cold, Zelios men's heavyweight (278g) base layer pants are designed to deliver performance in the harshest of winter conditions. These breathable moisture-wicking and odour-resistant leggings are made from pure merino sourced from Lanerossi (Estd. 1817). Tested on long multi-day treks in the Himalayas, and designed for extremely long durations of wear, these leggings have a perforated rear band to aid ventilation and will deliver outstanding thermo-regulation to keep you warm, and unlike synthetic alternatives, your skin dry. These base layer bottoms are a firm addition for all outdoor enthusiasts.
Pair with men’s mid weight merino long-sleeve top for the perfect base layer coordinated set.
Benefits of merino sportswear

Thermoregulating, wicking and comfortable to wear straight to skin
Naturally odour-resistant and quick drying
Lightweight and insulating protecting you from windchill
Crease-resistant fabric which holds its color and shape
Carbon-neutral, biodegradable and sustainable

Style summary

Thermal merino wool base layer bottoms
True to size
Heavyweight 278g knitted fabric
100% extra fine merino wool sourced from Lanerossi (Estd. 1817)
Skin-friendly, non-itch wool. Wear straight to skin
Please note these thermal leggings will appear sheer when worn and are not designed to be worn alone.

Wash care

Thanks to its antimicrobial properties which make it resistant to odour-producing bacteria, your merino activewear will not need to be washed as regularly. We recommend quick washes in the sink with cool water, and spot cleaning any stains. You can refresh your garment between washes by gently steaming it.

Hand wash* with gentle detergent, wool, or baby shampoo
Lay flat to dry on a towel
Apply a gentle iron with a slow steam
Do not tumble dry

*Why we use hand wash only merino wool

Machine-washable merino wool is treated with a heat-resistant plastic, which cracks as it is washed and tumble dried. Aggressive washing damages merino, causing the wool to pill more, lose its shape and appear worn quicker than caring for hand wash only fibres.
Overall, choosing hand wash only merino wool means items last longer and they’re more environmentally friendly.

Made in our factory in India using the latest Japanese knit-ting technology.

Made in: India

Fit notes
Black & Charcoal - Chan is 5ft 11" (180cm), Waist 32" (81cm), Inside leg 31” (79cm) and wears medium for a fitted look
True to size | Length medium 88 +/- 1cm with each size
  • Delivery

FREE SHIPPING on all orders over $200 in USA

Items are shipped to you directly by our brands, using tracked, contactless delivery.

All customs fees, duties and taxes are included - see Delivery page for full details, conditions apply.

  • Returns

Free returns within 14 days of delivery - see Returns page for full details.

For orders placed between 1st November - 20th December you can enjoy extended returns for account credit up until the 10th January!

  • Price Match Guarantee

If you find an item cheaper elsewhere we will match the price, see FAQs or Contact Us for full details, conditions apply. Please note we're unable to offer a price match for products sold through independent retailers, or being shipped internationally.


We check all our designers against our criteria - so you can shop sustainably with ease. Find out more.

Paul James Knitwear's sustainable and ethical guarantees:

Meet the designer

Paul James Knitwear

Based in United Kingdom

We are Paul James - a luxury, Leicestershire-based knitwear manufacturer. We strive

Discover More

Our Recommendations