Shimano RD-RX817 Rear Derailluer GRX Di2 11-Speed for 42T Max Medium Cage Shadow+ 2023 Ships within Australia In stock. Available via Click and Collect or Buy Online Share Loading Facebook Like button... Shimano RD-RX817 Rear Derailluer GRX Di2 11-Speed for 42T Max Medium Cage Shadow+ 2023 Ships within Australia In stock. Available via Click and Collect or Buy Online Share Loading Facebook Like button...