What are the correct units for input base_z (height) into Surface Volume (3D) when the z_factor is not default (1.0)?

I am working with a DEM which has lateral (xy) units of meters and vertical (z) units of centimeters. I need to calculate the volume below a height (measured in centimeters). I have used the following syntax to do this:

arcpy.SurfaceVolume_3d(r'C:\mydem.tif', r'C:\mycsv.csv', 'Below', height, z_factor=0.01)

**Should the base_z (height) be specified in units of meters, or units of centimeters?**

Note some related topics/questions:

How does z_factor affect Surface Volume (3D) units?

100 cm / meter * 1m * 1m = 1m^3 therefore if you have 50 cm then you have 0.5m*1m*1m= 0.5m^3 what is the factor needed to produce the conversion