The BAKCOU Rear Derailleur Hanger is a crucial component that connects your derailleur to your bike frame. It is specifically designed to break or bend in case of an impact, preventing damage to both the frame and derailleur. It is always a good idea to have a spare derailleur hanger on hand to ensure your bike is always in top condition. Please make sure to select the correct derailleur hanger for your bike model. Don't let a broken derailleur hanger ruin your ride.