It is class 4 for the price of class 2. good reviews.
For SDHC (Secure Digital High Capacity) compliant devices only
Not compatible with standard non-SDHC devices
SDHC Speed Class 4 compatible (will work with Class 2 devices)
FAT32 file system (industry standard)
SD 2.00 Specification (industry standard)
Size: 24 X 32 X 2.1mm (industry standard)
Unformatted capacity of 16GB (1GB=1000MB)
Use will vary depending on host device.