The Scully Intellicheck 3 Dual-Level Monitor System meets the revised National Fire Protection Agency (NFPA 407) and Joint Inspection Group (JIG2) standards. It monitors two independent optical overfill sensors, High and High-High Level and features Scully’s patented Dynacheck circuitry, providing continuous self-checking fail-safe technology. The original Scully system was designed for the U.S. Air Force in 2003, and has been eliminating overfills for military users for over 15 years.