Bibhusan, do you mean the three Kern-Paillard Macro-Switar lenses for H8? As Simon rightly says, 12,5-5,5-36?
if yes, they have a diameter of 32mm, all three, as you can read in attachment image from H8 instruction manual.
You can consider this thread interesting:
But I summarize here by saying that:
32mm filters are rare to find, it's more convenient to buy adapter rings. The measurement of adapter ring for you is 32mm male to...diameter of filters you want to buy or you have already!
I had so many (80A, ND, etc.) 49mm diameter filters because I always used them with the same H8, but with a Pan Cinor zoom lens with 49mm diameter of filter holder of lens hood. For this reason, in the end, I found a 32mm male to 49mm female ring adapter and I'm OK, I had no vignetting problems. But, attention, everything it can be different, vignetting risk depending on the size of the filters and size of the adapter rings. The biggest risk is with 5.5 lens, but I don't know how big this risk is. I did not have any vignetting problems, as I said.
Edited by Luigi Castellitto, 13 May 2018 - 07:06 PM.