They are made from a 90% polyester / 10% spandex thermal blend. Many styles are also fleece-lined for added warmth.
They are described as straight-leg with an athletic fit, a regular rise, and an ankle-length cut.
Common features include 4-way stretch, quick-drying and moisture-wicking fabrics, plus an elastic waistband to help keep them in place.
Product titles and descriptions position them as insulated for outdoor and ski use. Many options are fleece-lined to provide warmth without adding bulk.
Care instructions list machine wash and tumble dry; product descriptions note that these bottoms are machine washable.
They use a pull-on closure and an elastic waistband designed to hold the bottoms in place comfortably without squeezing.
They are described as a midweight thermal fabric.
Comfort details include a tagless design, spandex-based stretch to reduce bunching, and moisture-wicking or fleece linings that help prevent an itchy, wool-like feel.