Of the four options for XTR Di2 Front Derailleur Mounts, the Low Clamp version may be the most traditionally common among mountain bike frames. As the name suggests, it clamps low on the frame, very close to the junction with the bottom bracket.
The Shimano Low Clamp Derailleur mount is made of aluminum and weighs 38 grams. Compatible with the FD-M9050 and FD-M9070 Di2 front derailleurs, it will be an essential component to get you rolling with electronic gusto. This mount will fit 34.9, 31.8, and 28.6mm tubes since it comes with the necessary shims to accommodate these three seat tube diameters. If you have a smaller frame that does not have tons of space for the second water bottle cage, a Low Clamp mount will probably be your best bet.
Available in the color black, the Shimano XTR Di2 Low Clamp Front Derailleur Mount will have you on the trails in no time.