Kepler Briefs [Mens]

Ultrafine merino underwear


Breathable, wicking and odour-resistant merino undercrackers Core Spun with nylon for durability: building your base layer from the bottom up...

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Kepler Briefs [Mens] Ultrafine merino underwear


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This item is on pre-order. It is due to arrive in stock soon and should be available from soon. We'll keep you up-to-date with your order progress and despatch as soon as it is available.

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The Kepler Briefs are a breathable, wicking and odour-resistant heaven for your nether regions. An active cut, flat-lock seams and a high, low-profile waistband fit comfortably underneath layers. We also use exceptionally soft superfine (17.5 micron) merino from Australian non-mulesing farms – for happy bums and happy sheep.

Wool is a highly breathable material, transporting your body’s moisture vapour outside without feeling wet to the touch. As an ‘active fibre’, it also responds to temperature changes, keeping your bottom toasty in Scottish winter and cool and dry for running in the height of summer.

Wool is naturally odour resistant which means you get more uses out of your undies before consigning them to the wash bin and makes them ideal for multi-day backpacking trips - kinder on the planet and anyone you’re sharing a tent with!

We’ve used Core Spun merino for underwear, a technology with all the benefits of merino but with added durability. It’s still merino on the outside but a nylon and spandex core produces a yarn that’s harder wearing and rebounds back into shape better than 100% merino.


Key Features

  • Merino core spun with nylon and spandex improves fabric durability, recovery and stretch whilst retaining all the benefits of merino wool
  • Wool is highly breathable, naturally absorbing water vapour into the internal structure of the fibres before evaporating it, wicking away liquid sweat when needed
  • High warmth to weight ratio of superfine merino plus natural temperature regulation properties
  • Wool is naturally odour resistant allowing you to wash it less frequently
  • High, wide waistband and low-profile flat-lock seams are comfortable under layers

Vital stats


86% Merino / 12% Nylon / 2% Spandex (200 gsm) Australian non-mulesing superfine 17.5 micron merino


55g (Small)

Care & Environmental Advice

Product Care Information

The better you look after this merino garment, the better it will look after you. Give your Kepler a long, happy life with these tips: Hand wash your merino in lukewarm water, or gentle machine wash at 30°C. Darn any holes as soon as possible so they don’t grow. Avoid snagging, vigorous machine washing, putting your finger through the fabric, and hungry moths. ​

Size Guide
Men's sizing
Chest (inches) 37" 40" 43" 46" 49"
Waist (inches) 30" 32" 34" 36" 38"
Chest (cms) 94 102 109 117 124
Waist (cms) 76 81 86 91 97
EU 46 48 50 52 54
USA 36 38 40 42 44
This size chart indicates the body measurements our garments are designed to fit. Measure yourself as described below, and use the size chart to find your size.
Chest: measure around your chest at the widest part. The tape measure should pass under your arms, and be level from front to back.
Waist: measure around your waist at the narrowest part.
Hips: standing with your feet together, measure around your hips at the widest part.

The Details