A two level constant current driver is the is at the heart of this light.
Below, the "Piston Drive" batery pack is shown. The nickel plated brass battery housing or piston can be driven into the low and then high contact by screwing the "sleeve" onto the head or the "piston" can be driven forward for both levels by pushing it throw the sleeve with your finger. There is an O-ring and bore seal between the top of the piston and the sleeve.
A simple twist on/ twist off pak is shown below as an alternative and a third tube with a clickie switch in the tail could also be used:
A prototype of the "Piston Drive" is shown below:
Black Proto:
With the advent of a pocket clip, the knurl will be replaced with some shallow grooves:
Limited production lights are soon to come......
McLux-PD with 19 mm reflector (one of a kind):