I wanted a very small saddle bag that fit neatly under my saddle, was durable, looked good and held just what I needed it to. This one checks all the boxes. I can fit an inner tube, tire levers, CO2 cartridge, patch kit and small multi tool in in – but THAT IS IT, and just barely.
The clip-on feature is great. It is neat and clean and holds well. The bag opens easily and can be removed or replaced on the mount quickly and easily. Last but not least, it looks great on the bike.
This size is perfect for me. but it is as small as it gets. If you are looking to put any more into the bag than I've listed above, go with the small or medium.