Viair Dual Compressor Packs include two Chrome 480C's, two heavy duty 40-amp relays and a 165 PSI cut-on, 200 PSI cut-off pressure switch, to make installing a heavy duty onboard air system simple and affordable. All Dual Packs come with remote mount filter assemblies and mounting hardware. - Each Dual Performance Value Pack is rated to fill tank volumes up to 10 gallons.