Gas mask filter 40mm Nato

myminifactory

I know this is not 100% accurate but for what i needed its fine. Also the thread is just close to 40 mm nato since i couldn't find all the info on the thread. but it works in fine in the threads of a gasmask with a 40mm nato thread. V1 has a small gap where i tried to make it look like the original. V2 don't have the gap since it ended up being and issue for my need. I sliced it in 2 to make it easy to print.