This vertical saddle bag attaches to the seat post at two points, preventing it from swaying and providing stability. It also has side pockets and numerous internal compartments for tools, pumps, and other items, designed to keep things from moving around inside. As expected from LEZYNE, the build quality is excellent. There is some minor wear and tear from normal use, but no significant damage. Please refrain from purchasing if you are overly concerned about minor imperfections.