D4ās MCPCB is 2mm thick, all other MCPCBs are 1.6mm, it is highly unadvisable to use a thinner MCPCB which will create issues with thermal transfer between the head and the MCPCB as the Bezel is holding down the MCPCB by pressing down on the optic.
Neither should the flashlight be used without the bezel and optics in place, doing otherwise will overheat the LEDs.
The D4 will produce tremendous heat on turbo mode, and heat up very fast (10~20 seconds for the thermal protection to kick in depends on the cell), please make sure the bezel always be tightly enough on D4 although itās checked very well before leaving the warehouse.
The price has been increased once againā¦ :weary:
EDIT : ordered anyway, Iāve waited for such a compact e-switch flashlight too longā¦ and with that FW I could not pass !