400G MERINO WOOL BOTTOMS 400g merino wool bottoms by Filson Black (Black) Women's Merino Wool Base Layer Bottoms Heavyweight Meriwool Merino Wool Lightweight Base Layer Bottoms For Women MERIWOOL Meriwool Real Merino Wool Base Layer Bottoms For Men MERIWOOL Meriwool. Thick moisture wicking merino wool makes our expedition weight 400g Merino Bottoms ideal as a next to skin base layer in the coldest weather, or underneath waders in icy rivers. The wool is from merino sheep, prized for their ultrafine fibers that are soft against the skin, moisture wicking and odor resistant. Wool has been natures top defense against cold, wet weather for centuries due to its ability to insulated even when wet. Front fly and elastic waistband.