VIAIR 120 psi Air Source Kits come with a low amp-draw， 25% duty cycle， 275C VIAIR compressor mounted on a 150 psi-rated 1.5 Gal. air tanks with 5 ports. All Air Source kits come with a pre-wired pressure switch (P/N 20003 / 90-120 psi). The 120 psi Air Source Kit comes complete with a 1/4 in. NPT brass drains cock， 1/4 in. NPT ASME coded and certified safety valve， 1/2 in. NPT port compression fitting for 3/8 in. airline pre-installed. To use， simply connect the pressure switch to fused power， make a solid ground and connect an airline to the compression fitting. The use of a 40 Amp relay and an appropriately-rated fuse is strongly recommended to preserve the life of the pressure switch.

Most popular air source kit used to power air horns (does not include air horns)

All you have to do is connect the air hose from your air horn to VIAIR's air source kit， then follow your air horn wiring diagram

Vehicle's engine must be running before turning on the compressor

(Optional) you can also tap into the air tank to use the air source kit as a tire inflator

Follow the wiring diagram in the instructions or visit our website for the schematic