Low oil pressure sensor switch designed for generator applications. Replaces MPN 491657S and restores proper oil pressure monitoring so engines receive reliable protection during operation. Key benefits Restores automatic low oil detection to prevent engine operation under low oil conditions. Direct replacement for parts labeled 491657S, simplifying repairs and minimizing downtime. Durable construction for consistent performance in generator duty cycles. Simple installation for compatible units, reducing service time. What it does Monitors engine oil pressure and provides an electrical signal when pressure falls below the specified threshold. Works with generator control systems that rely on a pressure switch input to shut down or alarm on low oil pressure. Compatibility and fit Replacement for MPN 491657S and compatible with generators that use that part number. Intended as a directfit sensor switch for compatible generator models and control modules. Practical applications Emergency backup generators at residential or light commercial properties when a worn sensor needs replacement. Routine maintenance for rental fleets or service providers to ensure reliable generator start and shutdown behavior. Field for portable generators used on job sites where quick replacement restores normal operation. Notes for buyers Confirm your generator uses part number 491657S before to ensure compatibility. Handles the standard electrical and mechanical interface expected of generator oil pressure switches; refer to your equipment manual for installation torque and wiring details. This replacement sensor switch provides a straightforward way to restore low oil pressure monitoring on compatible generators.