SRAM Braze-On Front Derailleur Adaptor Fit a SRAM Red road braze-on front derailleur adadapter on your frame that needs a clamp on derailleur. The adapert is designed to work with the new SRAM Red front derailleur as it has the ability to be compatible with SRAM's Chainspotter (not included). Features Allows use of braze-on style front derailleur on a frame without a braze-on mount Aluminum with steel hardware 31. 8 or 34. 9mm seat tube | Sram | Braze-On Front Derailleur Adaptor | Black | 34. 9Mm