Medium Cage Rear Derailleur. Up for sale is a New Old Stock (NOS) Campagnolo Record 10-Speed Rear Derailleur (Model: RD4-REXM), in brand new, unused condition. This classic derailleur from Campagnolo’s Record series offers smooth shifting, lightweight performance, and Italian craftsmanship, making it a perfect addition for collectors or vintage bike enthusiasts. Model : Campagnolo Record 10-Speed Rear Derailleur Medium Cage.…