Each of the clues leads to an two or three-letter abbreviation. Solvers will quickly notice that the abbreviations on the left and right are reflections of each other. Connecting the pairs of reversed abbreviations gives this:
From top to bottom, the letters crossed by the lines spell out INTERNET SERVICE PROVIDER. The abbreviation for this is ISP, which can be reversed to make the answer, PSI, short for Pounds per Square Inch.
It would not be unreasonable for somebody to think the answer could be ISP, Pounds per Square Inch, or even Internet Service Provider. Fortunately, there is no penalty for guessing a couple options. Were the answer checker more sophisticated, I would have had it respond with confirm all three of those options as close.