Most listings specify a 90% polyester / 10% spandex blend made as a midweight thermal fabric.
They use a spandex-enhanced blend (about 10% spandex) and 4-way stretch construction so the fabric moves with you. Tagless construction is also noted for added comfort and reduced irritation.
They’re intended for cold‑weather and outdoor activities—examples include camping, skiing, snowboarding, and running. Product listings emphasize insulation suited for outdoor and extreme‑cold conditions.
They are described as having moisture‑wicking fibers and quick‑drying fabric to help reduce sweat and keep you dry.
Garments are described as midweight and repeatedly marketed as 'no‑bulk' fleece‑lined pieces that provide warmth without added bulk.