don't misunderstand me
Unfortunately, while the edge bristles catch a lot of what is on your upholstery/carpetry/cushions and what have you, they do NOT catch the majority of all things to be removed.
The main work is still done by the disc brush once you apply it the right way.
That zip brush should be redesigned entirely, just like so many features of the Kirby that have gone a long way since the 30s.
Why not have an outer body that literally forces the user to hold it the right way? Why not make it have some dimples or other distance-keeping protrusions other than bristles? It is the rotating disc that is still supposed to do all the work.
Why not make it with a substantial ball bearing?
Why not give it some more balance? (This wannabe counterwheight that was introduced with the G6/G7 is more than helpless what comes to keeping a high rpm.) I wonder who was the guy to think of this being useful.
I'd have some dozens of improvements for the old an coming-a-long way zip brush, but that would require more than just one post here.
The rim is doing all the work? This is NOT what I say, while it does in fact once the zip brush is used the wrong way, ok.
Overall I think a disk (compared to a roller brush) is doing a better job at twirling together all those loose and dangling hairs into a "vacuumable" blob of knotted hair, that is why the zip brush wins on dog hair.