This is a flashlight controller which controlls current by fast switching using electorical switch.
flickering is not visible for bare eyes) made by Blast off (See below).
I have seen one which takes place of Maglite's tailcap but never seen this kind of integral type one.
As this is an integral type, it fits in many flashlights(Caution: this device adds extra 4-5mm length
so flashlights with weak structure can be damaged).
I tested this with Toshiba 2D, Maxcell 4D(2*2 cells side-by-side) and it worked with no problems.
Operation is easy, turning the flashlight off and then turning it on in 3 seconds. it changes mode.
Using dimmer mode extends battery life as it's current cntrolled.
Choices like Ordinary lighting mode for long throw and Dimmer 2 mode for reading papers keeps running cost low.
Also, some of high power flashlights using halogen or xenon bulbs have high risk to break lens and reflector
by heat generated during long time run but the use of a controller will reduce that risk.
*We have no duty for troubles with linked website(company) introduces here.
Please keep in mind.
This is not a original flashlight's manufacturer's accessary.
The use of it may damege the flashlight or void manufacturer's warranty.