Shimano Dura-Ace RD-R9250 12Spd Rear Derailleur [IRDR9250F] at BikeTiresDirect
Shimano 105 RD-R7150 Di2 12-Speed Rear Derailleur [IRDR7150A] at BikeTiresDirect
Amazon.com : Rear Derailleur, Huazu Bike Parts Gear Shifter for Shimano RD-TZ31-A with Direct Mount/Hanger Mount for 6/7 Speed Mountain Bicycles : Sports & Outdoors