Let's face it, accidents happen. And when they do, your derailleur hanger sometimes gets bent. Most of the time it can straightened with a proper derailleur hanger tool, but sometimes not. And when you can't safely straighten it for precise derailleur function, you need to replace your hanger. This replacement derailleur hanger is made by Wilier for the Cento Uno SL, the Cento Uno, the Gran Turismo, and the Imperiale. Simply unbolt the old bent one and install the new one in its place. Fasten your derailleur and you should be able to get back on the road in no time. This replacement derailleur hanger does not include bolts, so you'll need to save your frame's existing bolts to attach it.