The drop is the voltage. If your driver is set to 3A, the drop will be 7.5V, if to 4A, then 10V. Works well - you can see Volts and Ampers at one screen.
I use it to set the driver current. Indeed, I did not find any test load which was described as behaving like a series of 2 or more blue diodes. It looked like all test loads were designed to mimic the behaviour of just one laser diode, so common voltage drop was in range of 3-5V if I recall it right.
I know this set does not look super professional, but simple things also work if there is no high tec stuff at hand when needed...
Just got one of these and checked the NTC, it reads 10k ohms at room temp and 20K outside, I did not warm it but my question is if this is needed at all or a 10k resistor in it's place or will the driver work without it?
p.s. I know a jumper/switch/pot is needed on the other side.
I lost the resistor on the bottom right (next to the 5V, Mod, and GND pads) while using a hot air solder gun. Any chance you could check the resistance for me?