FILLS 1 TO 4 TIRES TO INDIVIDUAL PRESSURE AT THE SAME TIME0-60 PSIACCURATE TO 1 PSIINSTRUCTIONS:TURN OFF VALVE WHERE AIR LINE CONNECTS. CONNECT AIR LINE - 150 PSI MAX. AIR LINE SUPPLY SHOULD BE MOISTURE FREECONNECT HOSES TO TIRES. THE FIRST TIME THE FILLER IS USED, BE CERTAIN TO SET THE REGULATORS BELOW 60 PSITURN THE YELLOW KNOB COUNTERCLOCKWISE TO LOW THE SETTING. NOTE THEY ARE MARKED RF, LR, ETC. OPEN VALVE. TURN YELLOW KNOB TO SET DESIRED TIRE PRESSURES. THEY CAN BE THE SAME OR ALL 4 DIFFERENT. PUSH KNOB DOWN TO LOCK ADJUSTMENT. FILLING TAKES 2 - 3 1/2 MINUTES. CHECK TO SEE IF COMPLETED BY CLOSING THE VALVE. THE 4 GAUGES ACT LIKE INDIVIDUAL TIRE GAUGESONCE CORRECTLY ADJUSTED, YOU CAN LET THIS SYSTEM RUN WITHOUT FEAR OF OVER FILLING YOUR TIRES, FREEING YOU TO DO SOMETHING MORE IMPORTANTWARNING: IF THE REGULATORS ARE NOT SET PROPERLY BELOW 60 PSI THE TIRES COULD OVER INFLATE AND EXPLODE, CAUSING SERIOUS INJURY OR DEATH