Ortlieb Back-Roller

These are 100% waterproof. They feature welded seams and a roll-top closure, meaning they will keep your gear dry even in heavy rain or through deep puddles.

The QL2.1 mounting system is highly adjustable and fits rack tube diameters up to 16 mm. The package includes inserts for 8 mm and 11 mm tubes, so they are compatible with the vast majority of standard rear racks.

You can absolutely use just one. The bags are symmetrical, so you can mount a single pannier on either the left or right side of your rack depending on your preference.

The bags feature a slanted shape specifically designed to provide clearance for your heels. If you have a bike with shorter chainstays, you can also adjust the mounting hooks on the back of the bag to position it further back on the rack.

The pair offers a total capacity of 40 liters. The roll-top closure is the key here—it allows you to compress the bag if you're carrying less, or extend it slightly if you need to squeeze in extra groceries or gear.

Not at all. The QL2.1 system is designed for single-handed operation. You simply lift the handle to release the hooks, and the bag slides right off the rack.