When sourcing annunciators for industrial or power plant applications, you must prioritize reliability and visibility. Key specs include the number of alarm points (windows), typically ranging from 4 to 128 points, and the window size (e.g., 30x30mm or 50x50mm). Ensure the device uses high-intensity LED illumination for long-term durability and low power consumption. Additionally, verify the response time, which should be less than 20ms for critical fault detection, and check for sequence of events (SOE) recording capabilities if high-level diagnostics are required.