Terrible for installation and the main straps are tight, meaning they won't fit on a moped seat. You would need a seat or a passenger seat with the dimensions of a sanitary pad. The zippers open a bit difficultly because they are close together, and some of them get stuck because you have to open them slowly and in parallel...whatever that means. As for the volume, it's good, but I wouldn't buy them again. It's better to get two backpacks for 20 euros and secure them with a buckle, you'll be much better off and more reliable.