Outdoor Research Airpurge Dry Compression Sack 10L Nylon Imported Fabric Performance: Waterproof, Air-Permeable Panel, Compressible, Durable, Fully Seam-Taped Air permeable/waterproof fabric band purges air during compression Hydroseal coated nylon is waterproof and durable Waterproof taped seams Internal zippered pocket doubles as small item and stuff sack storage