3 layers of laminate.1st layer: 100 % nylon.2nd layer: breathable polyester membrane.3rd layer: 100 % polyesternsions: 225 x 85 cmnsions: 40 x 8 cmht: 960 grproof, breathablerous cut, suitable for many sleeping bags 2-way zip push-button cover stripband with elastic and Velcro fastener.