This is an old magic lantern lens. Instead of a focus wheel arrangement, it has a twist focus. The focal length is approx 5 1/2", f3.5. The image circle is about 5" at infinity, so will be perfect for closeups on 4x5 and 5x7 if you want some swirls. 3 1/4" tall, 2 1/4" diameter at the threads. 266g ( 9.5 ounces). The marks on the glass around the edge in the last photo seem to be some grime I missed. It does not look like separation. The glass is in good shape, has a few cleaning marks like nearly all of these do. It's too windy here in the Midwest to go out and take a close-up shot outdoors, so I just pointed it out the window and focused at about 15-18 feet for the second shot. You can see the great fall-off and edge softness. Up closer for portraits, you'll get all the 'petzvalness' that people are looking for with these. It was on an 8x10 camera, so you can see the relative image circle size. Price: $135 shipped in the US. USPS money orders preferred. Overseas shipping is fine but will cost more. If sold to Australia, I can take a direct deposit.