High Frequency/High Output Pulse Start DE MH lamp MH lamps are required to be either open fixture rated or the lamp has to be installed in a luminaire with a protective glass shield. Nanolux MaxPar DE MH lamps use their exclusive patent pending secondary outer jacket design. Nanolux MaxPar DE MH lamps use an outer jacket of Borosilicate glass to meet the requirements for rating as an O-type lamp as per the USA National Electric Code 410.73(F)(5) and ANSI standard C78.387.