microSD ™ is an ultra-small, removable flash memory card format originally based on SanDisk's TransFlash card format. S3+ microSD ™ cards offer all the benefits of both our miniSD ™ and full size SD ™ cards and are specifically designed for mobile phones and smartphones with limited memory space. microSD ™ is backward compatible with TransFlash compatible devices and vice versa. It is currently the smallest memory card format commercially available. It is about one-fourth the size of a standard SD card but using an adapter can be plug in different devices.