It can measure the air pressure that enter the sprayer,adjust it to meet your requirements. The of the air pressure regulator is 0-12 (British unit of 0-180PSI). Air inlet thread is 1/4NPT taper of the thread, while the thread connecting the 1/4NPT internal thread. displays the pressure accurately and precisely, so as to adjust and control the pressure. Can be used with the standard guns, easy to use and very convenient.