VDO Heavy Duty Normally Closed Single Circuit 4 PSI Pressure Switch [230-504]Heavy Duty Normally Closed Single Circuit 4 PSI Pressure Switch Features: Ground Floating Connection # 8 32 Voltage 6 24V Circuit Normally Closed Single Contacts Silver Alloy Max. Pressure Range 4 PSI Terminals 2 *Sold as an Individual WARNING: This product can expose you to chemicals including LEAD which is known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings. ca. gov.