Amazon.com : Shimano Ultegra Di2 RD-R8050-SS Rear Derailleur - 11 Speed, Short Cage, Black : Sports & Outdoors
Shimano Ultegra RD-R8000 GS 11Spd Shadow Rear Derailleur - SoCal Bike - Oceanside, Carlsbad and north San Diego county's favorite bike shop, Bicycle and ebike rentals, sales, and service