Canon FL-F 300mm F/5.6 lens - It was the world's first tele-photographic lens that was incorporated with an artificial Fluorite optical element to contain chromatic aberrations common found in telephoto lenses. Without a date code, it's impossible to determine the production date. As far as I've been told, the date code was never indicated on FL lenses. However, Canon used to start their lens serial numbers at #10.000, so my number of #10288 indicates the lens was most likely released closer to the year off introduction off this model (1969) —But I'm guessing - has original case
