Looking for a Diffuser filter to fit GX30A3, GX25A3

[Luminesce]

I've been using an Olight M21 diffuser filter on the Eagtac GX30A3 and it fits snug. Also have a GX25A3 with an M22 diffuser on it but that required a few wraps of painters tape on the bezel to get the filter to fit snuggly. The lens on a prior M21 diffuser filter I had broke and I replaced it with the M22. I would like to have a spare M21 filter (two would be better) but it seems they are not easy to find. Anyone have insights as to what other diffuser filter may fit the lights I mentioned?

 

[Luminesce]

In case anyone needs a diffuser for the lights I mentioned above, I think I have one more option that can help you. I looked through a ton of archived CPF posts on my home computer and found this bit of info posted by Selfbuilt in his thread "UPDATE JANUARY 8, 2015",
4XAA Round-Up Review: Runtimes, Beamshots, Videos, Pros & Cons, and more!

http://www.candlepowerforums.com/vb/showthread.php?393409

Quoting Selfbuilt: "There are a number of diffusers out there from different manufacturers that can fit different size bezel opening. The fairly common ~40mm bezel opening used on many of these 4xAA lights means that the Nitecore NFD40 and Olight M22X diffusers are suitable."

Thanks Selfbuilt! I know the M21, 22's will fit the lights, now I can look for the Nitecore NFD40.

One more link: https://www.candlepowerforums.com/vb/showthread.php?354563

Selfbuilt UPDATE May 28, 2013: Based on a good tip from SCEMan, the Butler Creek Blizzard flip-open scope cover (size 5 - 1.6-1.69 inch, 40.64-42.92mm) fits perfectly. All you have to do is add your own diffuser film to the clear plastic lens, and you have a proper flip-style diffuser cover. I used some adhesive D-C-Fix diffuser material that I tested for jzmtl a few years back, for the pics below.

Thanks again to Selfbuilt for your dedication and all the hard work you have done over the years on CPF!