....TRAIN HORNS AND RELATED NEEDLARGE VOLUME/HIGH PRESSURE AIR....A DESTROYER ESCORT RUNS ON 600PSIX 1" PIPING....FIRE DEPARTMENTS ARE ABOUT 120# FOR THEIR HORNS AND USUALLY IT IS ABOUT 1/4" LINES.....MINE RUN 100PSI OR 600 PSI....IT MAKES NO DIFFERENCE.....EXCEPT IN VOLUME. IT IS ALL A MATER OF HOW MUCH YOU WANT TO SPEND.....CHEAPASS ME-ONLY WILL SPEND LESS THAN $100.... OUT THE DOOR..... GEOFKAYE AND THE RIVERCITY GIRLS