Question: are all kirby vacuum bags the same?
Answer: A: Yes. Kirby has a limited filtration system and it's largely contigent on the quality of the disposable vacuum bags, especially if you have an older Kirby vacuum. If you have a Kirby G3, G4, G5, G6, Ultimate G, or a Sentria made before 2009 then they can all use the same size vacuum bag.