Original Sandisk Micro SD Card 90Mb / s16gb 32GB 64GB Original Class10 32GB Memory Card for Smartphone/Tablet
About speed:
8GB / 16GB / 32GB-Class 10 SDHC
64GB / 128GB-Class 10 SDXC

About capacity:
32GB = about 28GB-30GB
64GB = about 58GB-59GB

Understanding speed grades
The SD card association uses two terms to define the speed of the card: speed grade and UHS speed grade.
The speed grade is the original grade used, and the number defines the speed of the card; 4 is 4MB / s and 6 is 6MB / s. 10 is 10MB / s and so on.
UHS (Ultra High Speed) uses the lowest write speed to distinguish cards; UHS-I Speed Class 1 has a minimum write speed of 10MB / s, while UHS-I Speed Class 3 has a minimum write speed of 30MB / s.
Speed is based on internal testing; performance may be degraded depending on host device, interface, usage conditions, and other factors. 1MB = 1,000,000 bytes
Please do not use a cheap card reader to test the Micro SD card. The speed of the Micro SD card will be affected by the low quality card reader.