The ortlieb saddle bag large is a compact and handy storage option which fits to your saddle rails and seat post they all come in either black blue green or red providing room for equipment snacks innertubes and tools for long day tours it tucks in nicely under the saddle and often functions as protector on bikes without fenders the additional fixation with velcro around the seat post provides firm and vibration free mounting reflective detailed trim is on either side and the backward