Someone is selling their 1200mm f/5.6 lens via B&H’s used site (see link here).
Here is some interesting info about the lens taken from the page:
The Canon 1200/5.6L USM, the longest fixed telephoto lens ever built by Canon, contains 13 elements (2 Fluorite) in 10 groups and focus’ down to 49.5′. With an angle-of- view of about 2° on a full-frame 35 mm camera, calling this lens a ‘tele’ is like calling King Kong a monkey.
Built-to-order by Canon from 1993 to 2005, each lens was hand-crafted at the rate of about 2-per-year and a delivery time of about 18 months. Only a dozen-or-so were ever made. Who bought them? National Geographic magazine and Sports Illustrated are known to own a couple, the Feds probably have a few squirreled away somewhere, and a few well-heeled photo enthusiasts.
Apart from a few minor cosmetic blemishes, this particular lens is extremely clean inside and out. Included with this lens is a leather slip-on ‘lens cap’, a fitted aluminum trunk case, and a prodigious measure of ego satisfaction. Weighing in at over 36lbs and an overall length of 33 inches, a sturdy tripod and pan/tilt head is highly recommended. Pack mule not included.