This is a nice saddle bag option for bikes where a traditional saddle bag mounting style won't work i.e. a Thudbuster or dropper post. The mounting plate goes on the rear rails on your saddle and the bag slides securely into place. The rolltop and coating of the bag will keep the contents dry in most situations. It also holds a lot more than I thought! In the .8L I have a tube, 2 C02's, air chuck, large multitool, chain breaker, and two tire levers. The rolltop closure allows for filling the bag as you need. My one qualm with the bag is the plate works itself loose after every few gravel rides. It's a quick fix, just tighten with a Philips. But, the rattling around can be obnoxious on a descent. Going to try some blue lock-tite on the fastening screws to see if that alleviates the issue. Other than that, it is an outstanding bag!