The Fulton Boiler 4-30-000052 Water Level Probes & Plugs Set of 4 is a replacement component set designed to monitor and maintain proper water levels in Fulton boiler systems. The probes detect water level changes within the boiler and provide signals to the control system, helping regulate water-feed operation and prevent unsafe low-water conditions. Used in commercial and industrial... https://www.partshnc.com/fulton-boiler-4-30-000052-water-level-probes-plugs-set-of-4