The bag is just right. It holds a tube, a couple of CO2 cartridges, and the CO2 valve, as well as a multi-tool, and tire levers. Just what I need for basic flat tire repairs or on-the-ride adjustments.
The strap loops around the saddle rails and tucks snugly up under the seat. By tightening the strap, the items in the bag are also held together so you don't get that annoying clank from the metal items banging into each other.
The zipper is a rubberized material that completely seals so you don't have to worry about water leaking through the zipper teeth.
All in all, a really nice, fashionable, retro style small bag. It matches up perfectly with my Brooks leather saddle and
It is also narrow enough that it doesn't rub against my shorts when I'm pedaling.