I have an Olympus focus ring PPRZ-EP07 for the 30mm macro that I was hoping to use in my new AOI UH-OM1-II housing. It seems just a bit too big in some dimension (I can't really tell once the housing is closed). I'm sure AOI will tell me to order their version, but I just wanted to check in case I was missing something obvious. The focus ring does fit the gearing, and turns if there is no camera/lens in the housing.