The product comes with 3 extensions only. Not only that, one of them looked like it had been set on fire (see photo). This extension was dark in color, like brass that had been heated with a torch. Given the price, one might overlook all of these issues, but they just don't work. They don't seem to screw in deep enough to hook the schrader valve itself. This creates pressure only between the two valves. I made sure of that by pushing the little metal dome in and when installed on the valve no air comes out. If no air comes out, the valve will not open and THE AIR IS NOT LIKE ANYTHING. I bought them to inflate my personal transporter tires to the optimum pressure. And now it's low and these help somewhat. Now I can't drive to work until I buy a replacement. How many problems can a product solve? 3 strikes and I'm out.