What are UHS interface and UHS Speed Class? Category : Specification / Capacity / Performance UHS (Ultra High Speed), the fastest performance category available today, defines bus-interface speeds of up to 312 Megabytes per second. It is exclusively designed for SDHC and SDXC memory cards, and compatible with SDHC and SDXC devices. Is the answer helpful? Related Why is the actual storage capacity of the product slightly less than the volume specified on the product's package? What is the difference between SD, SDHC and SDXC cards? Why does Transcend include the Proposition 65 warning? Technical Support If the answer can't help you, you can contact the Tech Support Department Get Started