An apparatus which enables a user of a pneumatic tool device, such as a nail
gun,
to determine the required compressor pressure needed to most effectively utilize
the pneumatic tool device and maximize the life of the tool. A compressor pressure
indication assembly on a nail gun comprising a nail verification assembly and a
readout assembly enables a user to verify the length and/or diameter of the nails
to be driven by the nail gun and set the compressor pressure accordingly.