The multiplexer is for both 12V and 24V. It's an MB SDS C4 copy. I can't answer your question as I have not used it on a 24V system only on my 12V W204 C320CDI and my 12V W639 115CDI Vito Van. It has been very good with no problems. I'm using full developer mode with Xentry DAS 10-2008 and Xentry DAS 01-2011. I've been able to remove torque limits, recalibrate the van speedo for different tyre size, adapt a new MAF sensor, reset control units and all sorts of things.
I would think it would work as well on a 24V Mercedes truck.
mbstarshop is selling Chinese copies to ... they probably come from the same factory.
I think it is useless to argue this here but it is not a "C4" clone even if a label talks about C4. That tool is a simplified PartD mux clone (this mux is often called "C3", which also is very misleading). The real C4 refers to the SDconnect mux which is a totally different tool, not only by the looks.
This one certainly is a Chinese clone, there has never been any official tool that looks the same. For us ordinary car owners a Chinese clone does not need to be anything bad, more the contrary, just be careful with the quality equally as with any Chinese clones of what ever product.
Have a look at the wiring diagram and this "Chinese C4" looks very much like the PartD wiring diagram. Next calculate the heat dissipation for the first transistor (TIP32C or similar). No way your tool would be able to handle the heat dissipation for that component if powered from a 24 V truck (remember how high the voltage goes when the engine is running).
Everyone, ignore what the labels state on these clones. It isn't even important. The tools are not made in France if the label says so, they do not always withstand 24 Volts even if the label says so. The serial number on the label is not what you can read from the SW, believe me or not...