This is used for dual caliper handbrake kits. The brake line runs from the master cylinder on the left handlebar directly to the 2nd caliper on the rear rotor.
***Please note: We are now selling Spiegler USA steel braided brake lines instead of HEL***
Most of the time, the M10x1.0 fine thread banjo bolt is used on European master cylinders (ie Brembo, Magura) and the M10x1.25 coarse thread banjo bolt is used on Japanese master cylinders (Nissin, etc.), with a few exceptions.
You can also leave a note in the comments box stating if you have a stock or aftermarket master cylinder and we can send the correct bolt.