This is the bare PCB you need to build your own tiny ~12mm FET driver! (Driver is not exactly 12mm; ears are wider but can be filed). DIY parts kit available here.
Should I Choose This or the MTN-10/11/12DD?
While the components and component layout are the same, the main differences are the driver outline and the non-exposed and removed copper around the component side border.
This is advantageous in a twisty light, because it is easier to electrically isolate the driver from the pill; however, for a clicky light, if the battery tube does not touch the driver or you can't solder to the pill, then this is not a good choice because you will have a difficult time getting a good ground.
The regular MTN-11/12DD is much better in these scenarios due to the exposed copper on the component side of the driver.
PCB Thickness:
Parts List: