NMicro 64GB Pro 90MB/s 600X Read 64G 64 G GB MLC Nand chip 4K2K Ultra HD Extreme Plus micro SD over Class 10 write speed 40~60MB/s read speed 80~90MB/s microSD microSDHC SDHC microSDXC SDXC UHS UHS-I UHS-II U3 Flash memory card without Adapter(actual free space 57.6GB) NMicro 64GB Pro 90MB/s 600X Read 64G 64 G GB MLC Nand chip 4K2K Ultra HD Extreme Plus micro SD over Class 10 write speed 40~60MB