OKI changed the design of their printers on several occasions and not all units use the same parts. This memo is to help explain the differences and aid in identifying the correct parts for a particular printer.
At this time, there are THREE to FIVE versions of some parts for both the 395 and 3410. Upwards of 80% of the currently installed units are version A, which use the oldest style parts. In most cases, the serial # of the unit is needed to determine which respective parts are needed for that particular printer. It is possible to retrofit several parts to make them work in any unit, so it is possible that the serial # information could yield incorrect results if that has been done in the past on that unit.