Agfa Copex Rapid film is a high speed microfilm re-rolled for still camera use. Keep in mind that "high speed" for a microfilm in this case means ISO 50, so despite the Rapid in the film's name, this film has a low ISO speed compared to other still camera films. But in the world of medical, scientific or microfilms then ISO 50 is indeed quite fast.
Agfa Copex Rapid has been on the market for several years now, dating back to at least 2017. It is supposedly a successor to the original Agfa Copex film which was an ISO 25 microfilm. Since it is designed for reproducing documents, Agfa Copex Rapid is characterized by high contrast, high resolution and super fine grain. Since most documents don't require the reproduction of much middle tonality, a film like Copex Rapid can worry itself mostly with blacks and whites and not worry so much about the greys in between. This can make Copex Rapid a bit of a tricky film to use for standard pictorial use, but if you embrace the film's super high contrast then it can be a fun and interesting adventure to feed this through a camera. Keeping it for overcast days where the lighting is fairly even can help tame this contrast, or you can go all in and shoot for a graphic black and white look.
Other than the contrast, the other thing you'll note when shooting this film is how sharp and smooth it is. Particularly when used in medium format, Copex Rapid has virtually no grain and with a high acutance the edges in your images will be super crisp.
Copex Rapid is coated onto a PET base, instead of a triacetate base. PET bases are known for being very clear and for processing very flat. In regard to the former, this can make Copex Rapid a good candidate for positive processing if you would like some b&w slides. As for the latter, while the film still has a tendency to curl up lengthwise it avoids "cupping" where the film curves edge to edge. This flatness can make printing and scanning so much easier as you won't have focus issues at the top and bottoms of the frames. PET bases are more prone to light piping and light leaks and the film apparently has an anti-halation layer to prevent this but still comes with the recommendation that it is loaded, unloaded and stored in complete darkness until processed.
This is a good film for someone who likes a lot of drama in their images. Or for someone missing the days of Kodak Techpan. Or just for someone who wants a different flavor in their photography.