These deflators work great. I've been using them for 3 months now. It's a little tedious to set up, but once you have it, you're done. I manually reset the tire pressure to the desired pressure first. Then I screwed the deflator onto the valve. I then dialed in the regulator until it was where I wanted it (11 psi). Then repeat this step with the remaining three on the same hoop. Then I tested them on three other solid tires and they work and have worked great with no adjustments ever since. It is important not to leave them on while driving. Pressure surges from punches, sticks, rocks, etc. cause pressure surge and each time this happens they spit out air. So just bleed, remove, replace valve caps, remove retarders or give them to your buddy to speed up the bleed process.