Kirby Genuine Surface Nozzle Assembly Hose Attachment Vacuum Cleaners Generation 6 Gsix G6 G6D G 2000 Limited Edition G2001

Q: Are the wheels plastic or rubber?

Outside is rubber, core is plastic.

Q: Does this work for the g4?

Yes it works on the G4 only difference is the color.

Q: Is this the only bare floor attachment for Sentria, Kirby. Will it fit mine, 6 years old

This will fit all Generation-series vacuums, G-numbers, Ultimate editions, Sentria, and Avalirs. Just may not match colors, they've used the same tools in different colors for decades, now.

Q: Just got the new head in the mail and underneath we have noticed the brissels are only on the edges and not the whole width like the original?

Consider that a design improvement. Dust balls are quickly pulled into the machine. If the bristles went across the entire width, dust balls would be caught by the bristles and then the user would have to clean them.