Universal SD
The Russian Doll of SD Memory Cards – fits a Micro or Mini SD card inside an SD card.
Universal SD is a standard sized SD card that can fit an additional Mini-SD card inside it. A Micro-SD card can then in turn fit inside a Mini-SD card sized adaptor. This means it’s possible to fit a Micro-SD card inside the Universal-SD card as well.
Universal SD cards come with a Micro-SD card that can store either 2GB or 4GB of data.