I have this one and quite like it: FASTFUEL DRYBAG X | Topeak
I’ve only used it on a couple of much-longer-than-usual rides, but it worked well and meant I could ride without having my jersey pockets fully loaded - a great feeling, I think it helps with comfort on the longer rides. I also used some adhesive protectors on the frame so that the base wouldn’t rub the paint, but it probably isn’t really necessary.