Question on Horn kits!

Hello! I have been just browsing some horns and was looking at the “Chrome Outlaw 3000 Train Horn” it looks afordable and effective. But anyways, using my common sence I realised these horns require the air to make the sound, so my question remains, Do the horns come with a air compressor? or is that a Separate thing to buy?

Thanks for your time!

THE OUTLAW 3000 ARE GREAT HORNS HERE IS A KIT WITH EVERYTHING YOU NEED TO MAKE THEM WORK http://www.hornblasters.com/products/details.php?i=outlaw-232-black-train-horn-kit BUT MY SUGESTION IS… SAVE SOME MORE MONEY AND BUY A SHOCKER KIT FROM WWW.HORNBLASTERS.COM… IN MY OPINION THIS IS ONE OF THE BEST DEAL HORNBLASTERS HAVE http://www.hornblasters.com/products/details.php?i=shocker-540-train-horn-kit THIS KIT COMES WITH EVERYTHING YOU NEED TO MAKE THE HORNS SOUND AND SCARE THE CRAP OUT OF EVERYONE… IF YOU WANT A REAL TRAIN HORN THAT ARE A LIL MORE EXPESIVE BUY A NATHAN AIRCHIME http://www.hornblasters.com/products/details.php?i=nathan-airchime-k3-540-train-horn-kit THIS WILL SCARE THE CRAP OF EVERYONE AROUND YOU AND 2 MILES AWAY LOL… HOPE THIS HELP