Set final target pressure using the + and – buttons. The LCD screen will show the target pressure. Connect air hose(s) to tire valve stem(s). FOR TOP-OFF ONLY: Push the “FILL/PURGE” button once. FOR NITROGEN CONVERSION: Push and hold the “FILL/PURGE” button for 2 seconds until the LCD screen shows “N2P”. When unit “beeps” and the LCD screen flashes the target pressure, tyre inflation is complete.