Question: The WFM7F05 has different configurations. What are the differences?
Answer: The different configurations are to support older instruments as well as new instruments. The O and N in the option refer to OLD and NEW style instruments.
OLD style is all of the CRT based instruments, including 1700 series waveform monitors/vectorscopes (except 1741C), WFM601 series, and the 760, 764.
NEW style is for the LCD based models, including the WFM700 series, WFM6100, WFM7000, WFM7100, AMM768, 1741C, MTX100 series and RTX100 series
The different sleeves used have different mounting points, and different patterns of holes for cooling.