For today's review we have the Kingston Class 10 UHS-1 Ultimate SDXC 64GB card. Kingston has been making reliable, high performance memory for many years. This SDXC card is no exception. It supports UHS-I technology and supports Class 10 performance when used in a non-UHS-I capable device. What is UHS-I? UHS stands for Ultra High Speed. The ?-I? denotes that the card should have at least a minimum write speed of 10MB/s, aka, Class 10 performance. You will commonly see this as a ?U? with a ?1? inside it. The Kingston Ultimate easily meets this spec. and is rated at 45MB/s write and 90MB/s read speeds.