The Survivor Roll tail bag fits perfectly on top of a luggage rack that attaches using Nelson-Rigg's unique "Full-Nelson" mounting system. Keeping this bag 100% waterproof, it features an air tight roll closure ensuring that no water enters the bag.; Electronically heat welded seams 100% waterproof Made from waterproof and durable tarpaulin PVC Compression straps easily adjust to volume of content Firm internal base plate helps support the bag Attaches using the unique "Full-Nelson" mounting system Coated outer material prevents slipping or marking Hi-Visibility reflective accents Lifetime manufacturer warranty 20.98 liter capacity Dimensions: 16" L x 10" W x 8" H