Shaft displacement equipment (VIBROMETER)

Hi,
We want to use Vibrometer proximity sensors TQ402 for vibration measurement of the gas compressor shafts.

I want to ask if anybody knows the difference between order numbers 111-402-000-012 and 111-402-000-013, appearing in different versions of product datasheet.

and also the same problem for AC/DC rear panel of VM600 system: 200-582-970-011 and 200-582-970-021.

has anyone here used these products before? any experiments?

Thanks in Advance