CoreyCoop
I was working with a three of these cards using the included adapter, and thought they were slower than they should be.  I just bought a full size Sandisk Ultra 16GB class 10 (all the same specs except size theoretically) for a different project, and it writes over twice as fast on the same computer! The write speed on this card is between 7 and 10 MB/s, the read seems to be 35MB/s, compared to the full size card with write speed of 22 to 25MB/s and a read speed of 42MB/s (this is from an imaging program, not a benchmark program, so it's not checking different sizes of transfer and the like).  Compare that with a Transcend 4 GB Class 4 card, the write speed is nearly identical (7 to 9MB/s), while the read speed on the class four is 12 to 13MB/s, significantly slower, as expected.The read speed is good, but the write speed is abysmal!  If it says "Class 10", it should be somewhat close to the Class 10 spec.I'm returning them.