The VPS421 has an voltage attenuation of 100:1 and has a fixed frequency compensation (or ‘scope input compensation’) that requires no adjustments by the end user, if used with a Fluke 190-series ScopeMeter.
Your last photograph shows us a VPS410-II-x series probe, which has a voltage attenuation of 10:1 and which allows for input compensation for scopes that have an input impedance of 1 Meg-ohm in parallel to a capacitance of 10 ~ 22 pF.
One of the most unique characteristics of the VPS421 is that it was designed and has been approved for working voltages up to 2 kV between probe tip (‘hot side’) and the reference lead, for application in which both sides carry voltages of different phase up to 1000V over ground, like in 3-phase power systems and drive outputs. This was true for the earlier VPS420, is true for the VPS421 as well.
In my materials, (like the Accessory Guide) I’m trying to support this specs-statement with the drawing on the right: safety rating of probe tip and reference lead 1000V CAT III individually, working voltage between tip and reference lead up 2 kV.
The other unique aspect of the VPS421 is, that the probe tip is not a tiny ‘pin’ as on most probes, but is a shrouded 4mm banana pin, as per the photograph on the right. And as such, it accepts standard 4mm alligator clips and the like to be attached directly. And that’s exactly what we’re including as a standard (see user doc).
For your convenience, find attached the user documents that come with the VPS421-x and with the VPS410-II-x, in the latter you’ll find information about making the input compensation.
With the VPS421 no such information is found because there is no adjustment needed, nor supported.
Attached is the instruction sheet for the VPS421.