This may have been discussed already but,
I've just discovered the perfect glass lens to fit a D size maglite (Does the C mag use the same size lens?). A 55mm photographic filter fits perfectly if you remove it from the metal frame. The diameter of the glass is exactly the same. I used a Hoya multicoated (UV) filter which should give excellent light transmission. The Hoya pro-1 and pro-1 digital filters have even better multicoatings but are slight overkill IMO. These are much clearer and more scratch resistant than the plastic lens, in fact you can't even see that its there.
It is slightly thicker than the plastic lens though, so the top section doesn't close fully with the stock reflector although the gap left is qiute small.
I've just discovered the perfect glass lens to fit a D size maglite (Does the C mag use the same size lens?). A 55mm photographic filter fits perfectly if you remove it from the metal frame. The diameter of the glass is exactly the same. I used a Hoya multicoated (UV) filter which should give excellent light transmission. The Hoya pro-1 and pro-1 digital filters have even better multicoatings but are slight overkill IMO. These are much clearer and more scratch resistant than the plastic lens, in fact you can't even see that its there.
It is slightly thicker than the plastic lens though, so the top section doesn't close fully with the stock reflector although the gap left is qiute small.