The Omron C200H-MR431 is a CMOS-RAM Memory Cassette (Memory Unit) designed for the SYSMAC C200H series PLCs. It provides expandable volatile memory storage for user programs and data, equipped with a built-in lithium battery for backup to retain data during power loss. This 4K-word memory module (comprising 3K words of User Memory and 1K word of Data Memory) plugs directly into the dedicated memory slot of compatible C200H CPU units (e.g., C200H-CPU01).