Securedigital sd sdxc card memory size 64 gb read speed 45 mbs write speed 18 mbs bus interface uhs i file format exfat operating voltage 27 36 v series transcend premium device class macbook dslr digital camera printer camcorder functions write protection switch manufacturers warranty 30 years sdhc class 10 uhs speed class u1 dimensions 32mm x 24mm x 21mm weight 2 g