It's definitely made by Schneider and is an OEM version of the 90mm f8 Super Angulon. It was made between 1976 and 1983. Unfortunately, Schneider did not engrave the lenses they made for Calumet with serial numbers. So, it's impossible to get a more definitive date. Very early (1976 through mid-1978) samples are single coated. Later samples are multicoated, and clearly labled "Multicoating" around the front element. Specs are identical to the 90mm f8 Super Angulon (216mm image circle at f22, 67mm filters, etc.)