Pentagon PX1 incandescent flashlight modified to host a NexGen 500 mA constant current converter and McR-27L deep reflector. Plastic window was replaced with sapphire window.

The build consists of a custom threaded brass can that houses the converter and screws into a thread in the body which was used originally for some type of anode contact partition. An "E-screw" Heat sink is used for the LED and epoxy bonded to the brass can. Since this design uses compression of the reflector against the window to provide a sealing force against an O-ring, an aluminium sleeve was made to provide a compression column between the heat sink and the reflector. It is shown below adjacent to the reflector and light engine. On the far right is a LED lamp assembly from the Pentagon L2 LED flashlight. In inset in the top LH corner shows the light engine threaded into the body

This mod has some similarities as well as distinct differences with the stock Pentagon L2 LED light and some comparisons are made:

The primary difference between the lights is the reflector. The McR-27L has a shorter focal length and is much deeper than the reflector used in the L2 or than other 27 mm reflectors, for that matter. In the inset below, the two lamp assemblies are lined up with the LED essentially in the same relative position. It is difficult to illustrate the differences in depth of the two reflectors.

Below is a pair of runtime tests with the mod on a single SureFire CR123 and the L2 running on a pair of SureFire CR123 cells. The runtimes of the two lights are very similar in duration.

Below is a beam shot with the lights side by side and the LED's equal distance from the target (about 10" away).

A comparative spectral graph of the two lights is below.

The calibration of the integrating sphere is not certain so the relative flux measurements have more value as relative comparisons and may both be equally off an unknown amount from absolute values.