Pivi - the 8mm Snap cap is the standard 8mm Blank/Gas cartridge that is popular in Europe. Fiocchi makes blanks of this caliber. I have the A-Zoom in my own collection. I can’t imagine why they made them, unless they sell them in Europe. The pistols are not widely used in the U.S., and even if they were, who needs snap caps for a blank gun?
I don’t know what the letters “A.B.” in your inquiry (and evidently their catalog) stand for. The cartridge in question has no headstmap, unlike most A-Zoom rounds. I suppose what was left of the head after the plastic “primer” is inserted didn’t leave room for a headstamp. There 6.36m/m (.25 Auto) snap caps are unheastamped as well.