Shimano Ultegra Di2 SM-AD67 Clamp Band Adapter
If you have a Shimano Di2 system and want to run it on a frame that's designed for a clamp-on front derailleur, then you'll need this adapter clamp. It's available to fit 31. 8mm or 34. 9mm seat tubes. Simply bolt it directly to your Di2 front derailleur braze-on style mount, and you'll be ready to position the whole assembly onto your seat tube.