Managing a Rollator when flying

[Doingitagain]

My mom and dad will be flying with me for the first time. They are both 92 and use canes. My mother also uses a Rollator, the kind of walker that has a seat. They will not be going to the parks. My concern is about flights...how do you handle the Rollator when flying? I am nervous about gate checking it and having it damaged. Their is no guarantee there will be room on the flight to bring it onboard. Do you use a special bag or case when gate checking?