Viking Horns V103C/1005ATK 3 Gallon Air Tank 200 PSI Air Compressor Kit Train Air Horn Air Tank Capacity: 3 gallon (12 Liter) with 6 ports Air Compressor: heavy duty 12 volts 200 PSI , 100% duty cycle Air ride suspension system With 240 PSI air gauge & 150 PSI sir pressure switch For high pressure air horns systems that require an on-board air system