Won in an eBay auction for $6.49. (The other two currently for sale on eBay are running in the $30-40 range.)
The description read: "I know nothing about lenses for cameras. What I do know this lens came in a leather pouch with the name Argus on the top of the leather container. Around the lens are the words Tele-Sandmar 100 mm F:4.5 Nr. 3696 C Enna Werk Munchen Germany. On another ring on the lense it says Made in Germany US-Zone. US pat. pend. It has screw caps on both ends. Everything seems to be operational. Opened up it is 3 1/4", close it is 2 3/4". Both measurements are with a sunshade attached."
Image © 2009 pashack49ic.