SanDisk is proud to announce our newest format and capacity to the Ultra II SD card family: SD High Capacity (SDHC) 4GB card.To support the higher capacity needs, SD cards are now requiring a different design. The new SD 2.0 specifications - which supports 4GB and up - is called Secure Digital High Capacity(SDHC). The SD Association has created and defined 3 speed classes to help you identify speed and performance capabilities/minimum requirements of SDHC cards and their SDHC host products. Details on the SD 2.0 specification: http://www.sdcard.org or SanDisk.com/SDHC Cards address data (read and write) at numerous speeds. Many factors impede this performance. SDHC guarantees a minimum read and write speed necessary to handle recording high quality video and audio. The maximum card speed may vary, but you can always depend on SDHC cards to meet your SDHC host product's high quality performance requirements.