What means SetStepFunction(G4double, G4double) function two arguments?

What means two arguments in function SetStepFunction(G4double, G4double) of class G4EmParameters ?

_Geant4 Version:_v11.0.2
_Operating System:_Ubuntu 22.04
_Compiler/Version:_gcc 11.4.0
_CMake Version:_3.22.1

The first is dRoverRange while the second is finalRange. You can find more on them in the corresponding part of the documentation: Mean Energy Loss — Physics Reference Manual 11.2 documentation

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I’m dealing with targets irradiated by bremsstrahlung photons. The average thickness of targets is about 80 micron. Values of arguments of the function equals to SetStepFunction(0.2, 100um). Are tհese values good for described task ? Also I set the next values for cut function.
void PhysicsList::SetCuts()
mm, “proton”);
SetCutValue(1mm, “e-”);
mm, “e+”);
SetCutValue(1*mm, “gamma”);

Are these values good ?