The Shimano Dura-Ace pulleys for the 7900 rear derailleur are OEM parts so they will deliver original Shimano quality and performance. Get more life out of the rear derailleur and keep the drivetrain smooth and friction-free. Includes both the tension pulley (lower pulley) and the guide pulley (upper pulley).
I have a 9-speed Ultegra RD-6500 derailleur that needed new pulleys and I made the mistake of purchasing a RD-6700/6600 pulley set as a replacement. This new set was nowhere near the same quality as the pulleys that originally came with the derailleur with noticeable drag and squeaking that would come and go when it needed lub. So I just purchased this RD-7900 pulley set after riding on the RD-6700 pulleys for a season. It's a big jump in quality and better than the originals that lasted many years of riding. These pulleys cost twice as much as Ultegra replacement pulleys, but I don't think that the Ultegras are worth buying because the bearings are so bad.
Pros: Works on Shimano 9-Speed deraileurs