Using SuperDuper! to backup an SD card
 

How can I have SuperDuper! backup an SD card when I insert it into my iMac.

Even though it's mounted in Finder I can't select it in SD!

I appreciate that it's not a 'drive' but is this in some way possible?

Is it formatted as HFS+ (Mac OS Extended)?

Well, that I don't know. It's 16Gb from my Garmin GPS and contains all of the maps and routes.

It reads fine in Finder and I don't really want to reformat it in case the Garmin then won't read it and I'll lose the maps.

Is there a way to check?

I can tell you definitively that it's not. We can't copy that, sorry.

I thought that might be the case.

I formatted another SD card as Mac OS extended and whilst the Garmin will acknowledge it's contents, it won't do anything with them.

Thanks for clearing that up.