It is marked with all sorts of stuff, including H05VV-F.
From the specification above it seems to be used for all sorts of things including PC power cables, and isn't particularly heat resistant.
I was going to check the cable stash to see what was there. I know I have some white flex on a reel but haven't yet checked it for markings.
At the moment I'm trying to work out if there is something extra special about the flex for this particular use, or if a generic reel of cable will do.
Cheers
Dave