It also fits on my SRT 7 its great for making your 40mm flashlight into a lantern. And if you have a SRT 7 you can dim it to any brightness plus the color modes.

I was not impressed with this Nitecore White Wand. Has a good fit on the Nitecore SRT7. Id rather use the Fenix AOD-M Diffuser (40mm)

I bought this for my Nitecore CU6 and SRT7 lights. Head diameter is 40 mm and it has exactly the same shape of NDF25 which I also bought for the P12. Fits perfectly, however, it is kind of long/big. Almost feels like holding a mini version of light saber (light dagger?) Comparing to the Fenix AOD-M diffuser, I would prefer the Fenix since it is much more compact, but works just as well. Regardless, this is very well made and feels durable. If you like the look of a mini light saber, go for it.