Shimano Gravel GRX RX815 Di2 2*11-Speed Rear Derailleur shift hydraulic lever caliper The 75mm cage version is

The 75mm cage version is compatible with up to 46T freewheel

Not compatible with Eagle cassettes and chains

It is also the lightest aluminum crankset in the market

X0 Transmission Flattop chain

And despite its smaller construction

Shimano Gravel GRX RX815 Di2 2*11-Speed Rear Derailleur shift hydraulic lever caliper The 75mm cage version isRD RX815 Shimano GRX DI2 Rear Derailleur Shimano Shadow RD+ 34T max low sprocket 11 speed With an integrated chain stabiliser mechanism, the Shimano GRX derailleur provides a quieter experience and shifting security and precision on mixed terrain. For rides on smooth surfaces, the derailleur features an On Off switch for the chain tensioner. The RD RX815 DI2 version offers the digital precision of Shimano electronic shifting and synchronised shifting.