Thermerino wool long johns.
Long leg thermal pants made from 100% merino wool and made in New Zealand:

Features

• Made of 100% Merino Wool.
• Merino wool offers superior warmth and comfort.
• Natural moisture wicking fabric draws moisture away from the skin.
• Merino fibres trap a layer of air next to the skin to keep you warm.
• 100% Merino does not trap body odour like synthetics, so you won't be throwing these away after a few months of use.
• Machine washable.
  
  Colour: Black, Navy, White
  Size: S, M, L, XL, 2XL, 3XL