@Chinners
I have two left.
The adaptor is compatible with the 48k / 48k+ / 128k and 128k +2 (Grey) as well as the latter Spectrum +3 and +2AB (Black)
You will need to prepare a hard disk device under Pera's Charea DOS - you can use DrvImg for that and then you can put snapshots onto the disk using the same said program.
The adaptor also has a NMI button feature that allows you to load and save snap-shots on the fly =)
I will eventually get round to doing a how too for these systems, sadly I am pressed for time over the next couple of weeks so that will have to wait.
If however you are still interested in having lots of fun with a little adaptor like this, just hit me up in PM =)