Universal IRIS lens mounting CLAMP.  Made in Germany. Serial #18650. Allows for mounting to a lens board of lenses in a barrel that do not have a mounting flange. Very handy accessory to have to mount your vintage brass barrel lenses that do not have a mounting flange. Good for mounting vintage brass barrel lenses from manufacturers like Baucsh & Lomb, Kodak, Cooke, Dallmeyer, Darlot, Voigtlander, Wollensak, Zeiss,  ect. This universal iris lens mount is in Ex/Ex- or 7.5/8 out of 10 cosmetic condition. Good working order. No dings or dents. Some patina around to the aluminum finish. Good working iris blades. This large iris lens mount will require a 7x7" or larger lens board. Distance between the mounting screw holes is 110mm between Overall outer diameter of this iris lens mount is 135mm. Maximum usable lens barrel diameter of this clamp 3 3/4" or 97mm. Smallest iris opening is 24mm. Very scarce to find vintage universal iris lens mount in this larger 3 3/4" size. This iris lens mounting clamp for brass barrel lenses sells with no reserve at a price of $375. I have LOT more BRASS barrel lenses, Kodak Ektar lenses, Large Format cameras and Lenses, Vintage and Collectibles and Soft Focus Lenses. More great buys on my other auctions, eBay Store and Web Page.