This is a lens that probably came out of some high quality copying or enlarging machine.  Focal length is 64.5mm and it shoud cover 35mm full frame, and likely more.  Aperture is marked 5.6, but I think we should trust the info on the front and it's likely f6 when wide open.  Aperture can only be stopped down to f11, as beyond that it wouldn't be as sharp, and this lens was optimized for maximum sharpness.  There's a bayonet into which the lens is screwed and then held in there via a set screw.  Optics are perfect and so are the aperture blades.  Very cool lens for someone looking to build a super sharp little camera, or you could also adapt it for use with some digital or 35mm film camera. 

Feel free to ask question if you have them. I’m a photographer myself, and have been buying and selling equipment on here for over 20 years now. I always do my best to describe the items as accurately as I can. Take a close look at the pictures, I try to show all possible flaws there, and so in real life my items look better than on here.

I'm putting higher prices on International Shipping, because I never know how much exactly it will cost to ship the items.   Once I ship your item, if you overpaid for shipping by more than $10 or so, I'll immediately send you refund on shipping cost.  Of course I'm always glad to combine shipping on multiple items.

Good luck bidding.