Pack Mate Compression Bag : Medium Place your clothing inside these plastic travel bags, seal end, roll up, and you're ready to go The air inside the bag with your garments is squeezed out a one-way valve at the opposite end Made with a triple-laminated nylon/plastic film which is sealed at edges with heavy duty edge seams Includes an improved anti-blowback zipper, waterproof and odorproof 20 x 16" holds 2 sweaters or 3 days laundry