Cheap differential probe with a AD8421?

[eTobey]

I read here, that a AD8421 can be used to build a differential probe. And with that, i found the following products:
https://de.aliexpress.com/item/1005005747516705.html
https://www.ebay.de/itm/355082474820

Can these products be used as a differential probe? If not, could they be modified in a simple way to accomplish that?

Signals would be up to 42V and i would be satisfied with a risetime of tens of nanoseconds.

[Kleinstein]

The modules seem to have no extra protection. So they are likely easy to damage. The input is also DC coupled only and the voltages need to be in a rather limited range set by the supply and CM range of the chip.
This makes them useful for special cases with small signals / low voltages (e.g. 1 V), if used with care. It than has low noise (less than most scopes).

The usual differential probes start with a high impedance divider and a differential amplifier to get a much larger voltage range. The shown amplifier is not ideal for the relatively high impedance (e.g. 100 K) of such a divider.
Speed wise the linked amplifiers are more in the 100-300 ns range for the rise time.