You have 2 choices now.....
These are the black clamps used to mount a round, remote or rectangular reservoir Brembo master cylinder to your bar, with a mirror mount on top.
These will fit any Brembo master cylinder where the screws that hold it are horizontal. Included 2 screws are random black, gold or silver but will match each other when ordered.
The LH M10 x 1.25 thread type is typically for all CLUTCH master cylinders. When your mirror is mounted and you are riding, the wind blows the mirror backwards which tightens it up.
The RH M10 x 1.25 thread type is typically for all BRAKE master cylinders. When your mirror is mounted and you are riding, the wind blows the mirror backwards which tightens it up.