After purchasing my new-to-me D700, the 32g card I had picked up at the same time wouldn't be recognized by the camera. Worked fine in a reader, software and firmware revisions are the latest that Nikon offers (upgraded them myself), camera just didn't like that card. While searching around for decent card prices, I came across this CF type 1 adapter to 2 micro SD cards. It seemed that the adapter was made with the idea that you would use a WiFi style card in the first slot, and an identical capacity card in the other. For $20, I went ahead and ordered it, as several other camera users claimed it worked for them. I've been using it for almost 4 weeks now, and I've had no problems with it, or the 16g micro SD card I'm using in it. The Amazon seller was Komputer Bay, item is Extreme CF Adapter. No affiliation other than being a satisfied customer.
YMMV
Caveat Emptor
Have a great day!
YMMV
Caveat Emptor
Have a great day!