Maybe you do not know that every Magnetic Card Reader Writers is unique. The bit density differs at the beginning and the end of the card. Knowing this fact, it is possible to examine if the tracks of the magnetic stripe cards have been written with one and the same magnetic stripe card reader / writer, in single or multiple swipes, or with different writers. All in all, the Magnetic Card Reader Writers is ideal for credit card verification, it is very useful and helpful for so many businesses