Shell: 92% Polyester | 8% Spandex Back: 100% Polyester Lining: 100% Polyester Top-layer: Durable and protective shell fabric has spandex yarn woven into it to create a 4 way stretch. Fabric stretches in all directions for maximum movement and comfort. Middle layer: Water resistant, breathable, flexible membrane has microscopic holes impermeable to water molecules and permeable to air/vapor molecules. Bottom layer: Brushed fleece allows for softness and comfort. Spandex elastic thread is woven into the shelf for vest stretch recovery.