Dawn
Although Amazon claim it is a C10 ultra fast Memory Card, it actually has much slower write speed than other C10 microSD card (it only scores about 60% of the normal speed). For example, I have tested it against my old Maxell C10 HC microSD card. The test was done by writing the same 3035MB random data from DRAM to empty microSD card through a USB3 card reader. The resulting time was the average value from 3 tests of each device:SanDisk Ultra 32GB C10/UHS1: 5m50.816s means 8.7MB/sMaxell C10 HC: 3m38.787s means 13.9MB/sThe speed is completely unacceptable for a Class-10 claim (13% lower than 10MB/s, the lowest boundary of Class-10 device), even the over-advertisement of SD card speeds are common (claiming 30MB/s for actual 12-15MB/s). It is almost a scam. Some Class-6 card will beat this "Class-10" card.