My elderly Givi soft bags have some rain covers, but they are thin and flap terribly at any speed. I have been using waterproof inner bags, but was giving up a bit of space as a result, so tried a pair of these
at the weekend.
They worked well, kept the rain out, the road mess off, and are made of robust enough material that they don't go mental in the wind. All good. And the panniers can be crammed full again.