The System Sensor DNR is indeed a new offering that replaces the FSD-751PL. While both detectors serve the same purpose, there are some notable differences. The DNR features advanced detection algorithms that enhance its sensitivity to smoke particles, improving early detection capabilities. Additionally, it incorporates advanced communication protocols, making it compatible with newer fire alarm systems and offering improved integration options. Overall, if you’re looking for enhanced performance and compatibility, the DNR is a suitable replacement for the FSD-751PL.