Originally Posted by Newt_on_Swings
It is a Leica Thread Mount (LTM) lens, it fits a variety of older Leica and other screw mount cameras. The thread is 39mm in diameter.
If its really long and unpronounceable it's likely to be a Leica as a general rule hahahaha
~Stone | Sent w/ iPhone using Tapatalk
~Stone | "...of course, that's just my opinion. I could be wrong." ~Dennis Miller