Check out the photos. This is walking up to my test tire, setting the Deflator PRO at 10psi. I monitored the pressure drop through a monster valve and inflation gauge.
4 Tire test..............Trailhead scenario
33 in. tires, 35psi
Changed preset pressure to 15psi.
(total time elapsed 38 seconds)
Removed valve caps, installed Automatic Deflator Pros and replaced valve caps as each deflator stopped.
(total time elapsed 6 min 20 seconds)
Checked each tire with Powertank gauge.