Once you get to the trail head you’ll want to let some air out of your tires (airing down your tires will allow your Jeep to get better traction over the rocks or in the sand). This can be a tedious procedure with a standard pressure gauge, so these automatic tire deflators have been created.
The standard tire deflator will let air out of your tires, with you checking every so often to see the remaining pressure. For alittle bit more you can get automatic deflators that will air your tires down to whatever PSI you specify.