The two-piece construction of this saddle pack for globetrotting bikepackers is made up of a lightweight, waterproof dry bag with a buckle closure roll-top and air-release valve, and a harness with a bungee cord and gear loops on the top, and a reinforced base which makes loading and unloading quick and easy during short rest breaks, because the dry bag can be detached while the harness stays on the bike. The two buckle straps and two hook & loop straps adjust to a variety of frame sizes and tube diameters, including carbon bikes.  Disclaimer: Sand, dust and incorrectly packed bags can make the paint in contact areas become dull or scratched over time. To avoid any chafing, you can protect the frame or rack with foam inserts or protective film before attaching bags or panniers.