Viair Dual (2) 400C 12 Volt Chrome Air Compressor Value Pack400C Dual Performance Value Packs include two of VIAIRs 400C compressors, two heavy duty 40 amp relays and a 110 PSI cut on, 145 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.