Someone in the USA has made a very helpful video on this topic. I recommend you watch it.
But first, I have some comments on the torches/flashlights used in the film. They are all low power. I used to offer the exact 3-in-1 torch she shows (It was FT2), but no longer – for three reasons: First, shipping and the low Australian dollar made them very expensive – nearly $600 retail then, more now. Second, all three options in the 3-in-1 are weak (equivalent to FS2, FM2 and FL0) compared to powerful single wavelength torches now available. Third, you can get three much more powerful SW, MW and LW torches for much the same or even lower cost.
But all the information in the video is correct.
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