Kyoritsu used EV's 9, 12 & 15 The camera/meter is set for ASA 100 as a standard value.
When changing levels the knob had a mechanical feel and sound to it more like changing ND filters not like rotating an electrical switch.
The tester also allowed changing the "K" factor to a value used by the camera maker.

While fiddling with the "K" knob there was a slight difference in brightness possibly in color temp.