Im trying to change my rotors and there is something similar to a torx head but has many more teeth that holds the caliper bracket in place. I need to know what its called so I can get a socket for it and figured someone here might know exactly what its called.

 

It is called a 12 point socket. I can not remenber the size, but it is not unusual because I was able to find one in my tool box. I think it was 12mm.
Cheers