The Shimano GRX Di2 12-speed derailleur features an integrated wireless connection unit and a charging port, allowing for fast and reliable shifting during rides on mixed terrain as well as easy charging. The integrated Shadow RD+ technology prevents chain slap and ensures precise shifting even in rough terrain. Thanks to the built-in ON/OFF switch, removing the wheel is also easy. The RD-RX825 is compatible with 11-34T and 11-36T 12-speed cassettes and supports both full and semi-synchronized shifting modes, enhancing customization for the rider.