Most listings show dimensions around 20 × 36 inches, with lofts typically ranging from about 5 to 9 inches.
Several use multi‑chamber or “pillow‑in‑a‑pillow” and layered designs (for example, an inner feather core with an outer down chamber). Ergonomic or gusseted styles are also described to help maintain shape and loft.
Listings include feather and down (including goose feather and goose down), blended feather/down mixes, kapok, and mentions of other non‑down fibers that aren’t always specified.
Descriptions indicate an ergonomic or oval gusset helps the pillow hold its shape and maintain loft, offering a balance of softness and support.