Casio Rock c731 Phone Professional Kingston MicroSDHC 16GB (16 Gigabyte) Card for Casio Rock c731 Phone with custom formatting and Standard SD Adapter. (SDHC Class 4 Certified) Share your content collections with friends, family and colleagues easily. Kingstons removable storage solution specifically designed for mobile phones with expansion slots. Its ultra-small size consumes very little power from your handset, to give you longer battery life on your phone. Now you can instantly move pictures between multiple devices for sharing and printing using this card as well.