Malkoff Devices ... many of you may already be familiar with the Malkoff modules and flashlights, but if not... they are not inexpensive, but if you have a quality LED light that you depend on....

the module is machined brass that acts as a heat sink to allow longer run time before your driver over heats, and the LED and supporting electronics is "potted", encased in resin... coupled with a well designed heat dissipating host flashlight body, heat is transferred for much longer use

https://malkoffdevices.com/collections/surefire-drop-ins-for-6p-g2-c2-etc-6-9-volts