If you're into biking, you know how frustrating it is when your derailleur hanger breaks - and of course it always happens at the worst possible time. This Derailleur Hanger 442 is a solid replacement option that comes with the M8 chainring bolt mounting hardware you'll need for installation. The aluminum alloy construction means it's durable but still has that slight flexibility that helps it absorb impacts (which is the whole point of derailleur hangers - they're designed to break instead of your frame). Now, super important warning here - before you install this or ANY derailleur hanger, you absolutely need to check your rear dropout alignment. If your dropouts are bent or misaligned, you'll just keep breaking hangers no matter how many you replace. The compatibility is specific to certain bike frames based on brand, model, and production year, so make sure this is the right hanger for your bike. Always compare the photo of this hanger against your broken one - if they don't look identical, it won't fit properly. Having a spare hanger like this in your toolkit is just smart biking maintenance - because when this thing goes, you're not riding anywhere until it's fixed.