The System Sensor B224RB-WH is indeed a new offering in our lineup. Unlike the B324RL, which is a 4-wire, photoelectric smoke detector, the B224RB-WH is a 2-wire, rate-of-rise and fixed temperature heat detector. It’s designed to provide faster response to heat rather than smoke detection. While it may not directly replace the B324RL in terms of functionality, it can complement your existing system by enhancing heat detection capabilities. However, it’s crucial to verify compatibility with your current setup, as wiring requirements and compatibility may vary. Feel free to reach out to our support team for further assistance in determining compatibility with your system.