Quality Bike Saddle Seat Wedge Bag Quick Release 100% Waterproof Heritage Retro Brown

To be honest, I wasn't that impressed with this. The bag itself is made of a pretty cheap-looking PVC and the zip doesn't look as though it will take much wear. It also hangs a good way under the seat and, consequently, the saddle must be pretty high to give clearance between the bag and the back wheel. On the plus side, the mechanism attaching it to the saddle is pretty sound. However, I took it off after a week or so and changed it. Buy something else.