I have been using this Staun product for at least 10 years while visiting Cape Hatteras National Seashore. (I only bought new ones with this purchase because I "lost" my originals). After going to Hatteras since the mid 70's and years of using my "welding shears" to depressurize to 16psi, my fiancΓ© gave me my first set. I'm not even trying to sit on my 5 gallon buckets anymore. Fuck these babes one by one. When the fourth one is installed I go back to the first one, delete it, keep going around the truck and delete them all. I wish I could inflate tires just as easily. The instructions say they are preset at 18psi, so I'll have to manually adjust them before my next ride. never mind I need to deflate a tire to 16psi for 4 deflators and then re-inflate a tire. I think I'll sit on my bucket for the initial setup. I read so many reviews about doubles (cheaper) but decided my first set is so good (until they ran away) why bother trying cheaper ones. Yes they are expensive but make sure you put them away and don't borrow them. Over the years they will cost you between $6 and $8 a year.