Agfacolor CN 17S” (S for Special), introduced in 1966 with a film speed of 40 ASA (ISO). This film was available in roll film sizes, 35mm cassettes of 12 and 20 exposures, and Agfa “Rapid” cassettes.
Agfa’s print ads in the 1960 advertised the film as (actual text from ad): “Agfacolor CN17 Special is a brilliant new double masked colour negative film specially made for today’s most creative and critical amateur photographers. even if you’re a reversal film addict, you’ll be amazed at the superior quality of colour enlargements you get from Agfacolor CN17 Special. Buy a roll now, from your Agfa-Geveart dealer (from 8s/6d = 43p). Double masked for purer, brighter colours. Speed 17DIN/40ASA. Extra fine grain and high definition. Better colour separation and reproduction. Very wide exposure latitude.”
Need to develop this old roll of film? Trust TheDarkroom.com with over 40 years of experience
Source: https://www.photomemorabilia.co.uk/Colour_Darkroom/Early_Agfa.html