These are the ''Low-Capacity'' drives from Vortex, for use on CPC 664/6128 or CPC 464 with DDI-1 (ie. on computers that already have a FDC and AMSDOS). There doesn't seem to be anything special about this product, just an off-the-shelf disk drive, shipped with a CPC-specific connection cable.
AMSDOS can only access 40 tracks. TO BE CONFIRMED: Are the drives 80 track, double sided? Is there any way to access the second side with AMSDOS (e.g. side switch??)
== Vortex -X Drives (720K/disk) ==