Wheels Manufacturing Inc. Emergency Derailleur Hanger
The Emergency Derailleur Hanger is a great thing to bring along on rides because it lets you temporarily replace a hanger that is damaged or broken on a ride. The Emergency Hanger works with most frames and derailleurs and allows the use of most gears, and more importantly, for the bike to be ridden instead of pushed or carried. So, it ensures that you can get home safe.