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NEW OPEN BOX / OLD STOCK... (Original box with some damage...)

**The ESL 500N Series conventional two-wire and four-wire photoelectric smoke detectors have intelligent software and digitally processed sensing capabilities. This intelligence, coupled with the ESL patented optical sensing chamber, means the ESL 500N Series quickly and accurately detects smoke. CleanMe compatible software, self-diagnostics, and dust (drift) compensation are standard in every unit. The ESL 500N Series offers application flexibility with optional auxiliary relays, rate-of-rise/fixed temperature heat sensors, isolated heat sensors and/or 85 dBA temporal-three sounder