THIS IS USED FOR EARLY HOLDENS AND FORDS PRE 1968 TO UPGRADE BRAKES FROM SINGLE CIRCUIT TO SAFETY BRAKE SYSTEM.

EXAMPLE.  IF ANY PART FAILS IN A SINGLE CIRCUIT SYSTEM THE BRAKES DO NOT WORK AT ALL.

IN A DUAL CIRCUIT IF A PART FAILS IE: REAR YOU WILL STILL HAVE FRONT BRAKES OR VISE VERSA.   THEY ARE A MUCH SAFER BRAKE SYSYTEM AND THIS ITEM GIVES YOU SURITY OF SAFETY.

This is a very hard to get item.  as of the bolt pattern up down lay out.