When you're planning on moving a mattress or storing patio furniture, use a ShoulderDolly Mattress Bag. ShoulderDolly Mattress Bags come in a variety of sizes and thicknesses to protect your investment. Made with polypropylene, ShoulderDolly Mattress Bags will prevent dust, dirt, and water from coming in contact with your mattress, box spring, couch, or patio furniture.