They are custom brake caliper brackets a Mercedes Benz W212 AMG. They are used when larger diameter rotors are installed. The link is for a thread on upgrading the brakes. Scroll down to post #29 for a picture of the bracket.

these are custom cnc milled big brake caliper adapters usually used to fit brembo six pistons to some other car, you will need more information like bolt spacing to get a better idea of what they fit my best guess is that they fit the profile of these bmw six piston calipers

References:

https://f10.5post.com/forums/showthread.php?p=20908997

Reason:
the 2 closest threaded bolt holes are 110mm center to center and the 2 holes on the end are 257mm center to center. WIll that help?

They are custom brake caliper brackets a Mercedes Benz W212 AMG. They are used when larger diameter rotors are installed. The link is for a thread on upgrading the brakes. Scroll down to post #29 for a picture of the bracket.

References:

https://mbworld.org/forums/w212-amg/726624-big-brake-kit-upgrade-cheaper-then...