Sat nav SD card

[greeneunos]

Hi this is first post , I have a b6 2010 Passat I have changed the radio for an updated one which has gps etc I think it’s a RNS 510 it may be a replica as I didn’t see a VW part number on it and it didn’t need a code , it has 3 slots at the bottom of the unit , on the left GPS middle USB and right SD, it looks like a micro SD for the nav I need ,as the SD card in My Audi is twice the size of the slot in the Passat head unit , I don’t seem to be able to find mini SD GPS card on eBay ? also how do I know if it’s android or Windows? Any ideas thanks in advance mike