Hummer 2003 H2 Owner's Manual page 146

Accessory Inflator (If Equipped)
Your vehicle may have an air inflator system. The air
-
inflator is capable of re inflating the vehicle's tires if
they have been deflated. You can also inflate things like
basketballs, air mattresses and bicycle tires.
The air inflator kit is located in the spare tire cover.
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The kit includes a 22 foot (6.7 m) hose with three
nozzle adapters.
The engine must be running and the gearshift lever must
be in PARK (P) for the inflator to operate.
2-64
The air inflator is located
in the rear compartment
on the passenger's side
of the vehicle.
To use the air inflator, attach the appropriate nozzle
adapter to the end of the hose if required. Then attach
the end of the hose to the object you wish to inflate.
Remove the dust cover from the outlet and attach the
hose to the outlet.
Press and release the switch to turn the inflator on or off.
When the inflator is on an indicator light will be lit.
When done with the inflator, place the inflator kit
accessories in the pouch and store it properly.
If your vehicle is equipped with the air suspension
system, load leveling will not occur with the inflator
hose attached to the inflator outlet. See "Air Suspension"
in the Index.
CAUTION:
Inflating something too much can make it explode,
and you or others could be injured. Be sure to
read the inflator instructions, and inflate any
object only to its recommended pressure.