Personally, I use it on my scooter in a small rack on the back wheel. Its capacity is excellent without having a bulky profile. It fits a full waterproof set (pants-jacket) + my work lunch and in the side pockets, the charger and some accessories (lock, etc.) which is exactly what I wanted for my everyday life. Just a little attention because it is not exactly as it appears in the picture (even on the Author's website, there are some incorrect photos), the top part when expanded is slanted, not flat.