I recently ordered this item and I am extremely disappointed with this. Because I received a duplicate item. Since I have already used Mastech product before, I was very sure that what I received was not original. So I purchased a original product in a store near by. Fortunately I was able to get the same model in a store. Please see comparison pictures. The one that is shown on right is what I received from this supplier. There is no Mastech logo or serial number. Beware of fraudulent suppliers who uses the brand name and dump the cheap low quality products.