Uses PERTEX QUANTUM, which is excellent in lightweight, water repellent, tear strength, seam strength, and weight ratio. Inside is ALLIED's European white goose down 90% Feather 10% (800FP). Bore fleece at the base of the hood prevents nylon from touching the neck. Bonded reflector zipper pocket is on the waist. The fit can be adjusted with the hem drawcord. The story of Allied's down can be serched from the attached tag.