Hello blgoode,
For me a 22 ohm resistor works well at nights and provides just enough light without losing the night vision in a 1 cell body using either a primary or rcr123. I would suggest that you buy a few extra resistor PCBs of different values and try for yourself. That way if you decide to run a 2 cell body you can change the PCB to suit your needs. You don't hear much about these two stage switches any more with the electronic controls now but I still think it is a great product. Push lightly to get a dim light, and push harder to get full power!
9x23
