Out of the roughly $300 I've spent a fastech I have had about $30 worth of duds. Read the reviews and try not to order brand new mods before the fixes, if required, have been applied to the design. Not to mention that the price is at its highest. Let someone else field test em. Once I started doing that, no more duds. They usually arrive pretty filthy. Machine oil and other junk but at those prices I don't expect a thorough post production cleaning. If your not in a rush china can be your friend.