This product looks very sleek and stylish, and is easy to quickly attach and detach. It does run a bit small though. (Lezyne makes another saddle bag with the same attachment system that is slightly larger). In this bag I am able to include 1 spare 700x25 tube, 2 plastic tire irons. 3 C02 cartridges and a CO2 inflator, 1 allen wrench, and 1 pre-glued patch kit. It's a tight fit but works for these items. If you prefer to carry a second spare tube, than the other Lezyne saddle bag would be a better choice. I like the attachment system on this bag. No straps needed around the seat post or seat. I have my seat slightly back in relation to the seat post, so there was plenty of room for the attachment system. If you ride with your seat forward, this *might* be an issue for you.