REOPUS Hall Effect Circuit Board. JaguarÕs problems with the Lucas OPUS ignition fitted to V-12 E-Types and early XJ-12s are well documented. While sophisticated for its day, OPUS failures were common and age has done these components no favors. REOPUS was an updated amplifier circuit board that cured all of these problems and made a V-12 run like never before. REOPUS H, for ÒHall Effect,Ó is another huge leap forward; it also now replaces the pick-up unit, many of which are now failing due to age. Must be used in conjunction with one of two pickup units: 08-1042 (two male and one female connector) or 08-1044 (one male and two female connectors). For more information, click the "Documents" button below.