K-Edge Braze-on AdapterKit SL 31.8, Gun Metal Chain Catcher solutions for Braze-on and Clamp on mounted derailleurs Enhances the overall function and shifting performance of your drive train. Protect your valuable frame from damage caused by a derailed chain. Engineered to function as a ramp that guides your chain on to the small chain ring. CNC machined in Boise, Idaho USA