This Kit Consists Of: (2) 5 Gallon Black Air Tank 30" by 7.5" (1) 444C model Viair Air Compressor  (1) Pressure Switch with Relay (110 PSI on, 150 PSI off) (1) Reducer (1/8" NPT F to 1/4" NPT M) (1) 1/4" NPT 175 PSI Safety Valve 1) 1/2 NPT Solenoid Valve (25) Feet 1/2" DOT Tubing (1) 1/4" Drain Cock (1) Wiring Kit (1) Fuse Holder, This is a dual tank kit that provides 10 gallons of air storage. All tanks are independent from each other. This may be used on all Train Horn Kits and can substitute a 8 or 10 -gallon tank..