RoofBag Carrier Liner Bags for Easy Packing (Set of 3) Accessory for RoofBag Car Top Carriers (RoofBag Carrier Sold Separately) Simplifies organizing, packing, loading, unloading, unpacking, and accessing your load: pack and handle each duffle bag separately. When full, helps keep the aerodynamic shape of the car top carrier, for fuel economy. Made of rip-proof and water-repellent black polyurethane-coated polyester. Each liner bag holds up to 50 lbs of gear. | Genuine YKK zipper slides smoothly and never jams.