I think that this product by itself is a great product.  However, not all devices is built for microSD XC.  And not all devices like pad and phone that specifically states that it features microSD with compatability to microSD XC.  This happened to me.  Since I just bought a new pad, I thought that it would be compatible.  However, it did not.  the microSD XC is formatted with exFAT so my device can detect the hardware but it can't write or read from it.