product highlights Designed for sports camcorders, tablets, smartphones, any other microSDXC-compatible devices, the 64GB High-Performance 633x UHS-I microSDXC Memory Card from Lexar can be used to record Full HD, 3D, and 4K video. This card has a capacity of 64GB, is compatible with the UHS-I bus, and features a speed class rating of U1, which provides minimum write speeds of 10 MB/s. In case your device does not support the UHS-I bus, this card also supports the Class 10 standard, which also features minimum write speeds of 10 MB/s.