Unknown Lens mount

[Khwezi]

I found a Soligor 135mm f2.8 at a thrift shop, but I can't figure out what lens mount it is. I looked and the closest I thought it could be is Exakta mount. I would really appreciate any help anyone can give me. The mount piece on the rear of the lens comes off. I tried to take some detailed shots. If i can take any other shots that can be helpful please let me know. Here's the link to the pictures of the lens: http://imgur.com/a/V4zmj

[Aswald]

Does look like the EXA mount.

[Guest welshkc]

Soligor used a t-mount threading.  There are t-mount adapters available for the X system.  I use one on my Soligor 650mm mirror lens.