System Sensor COSMO-2W


12/24 volt, 2-wire, system-connected, combination carbon monoxide/smoke detector with RealTest technology

5 in stock | Availability: Additional Units Available + Express Shipping Options

  • Factory New
Brand: System Sensor Part #: M03B-3129 Categories: , , Manufacturer Part #: COSMO-2W Tags: ,


The i4 Series combines CO and smoke detection into one device, requiring less wiring and fewer back boxes than two separate devices. The i4 Series is compatible with i3 (2WTA-B or 4WTA-B), so an attractive CO monitoring solution can easily be retrofitted into existing i3 installations. The i4 Series CO cell can be easily replaced at end-of-life, resulting in a much lower life cost than having to replace the entire detector.


Weight 0.60 lbs
Dimensions 5.50 × 5.50 × 2.50 in



System Sensor





Detectable Gas

Carbon Monoxide

Detectable Medium

Gas, Smoke

Production Status



  • Single device for CO and smoke detection that uses less wiring and fewer junction boxes
  • Compatible with a wide range of control panels with the use of the required i4 Interface Module.
  • Sends distinct smoke and CO signals to the panel
  • Sounds Temporal 3 for smoke and Temporal 4 for CO
  • Built-in 85dB sounder
  • LEDs display both CO and smoke status
  • External IR LED provides extended range sensitivity testing
  • Versatile mounting allows for wall or ceiling placement
  • Easily replaceable electrochemical CO cell with 10-year end-of-life timer that signals the panel and chirps to alert the homeowner
  • RealTest® enables functional test using canned CO
  • Drift compensation and smoothing algorithms provide false alarm immunity
  • Compatible with SENS-RDR sensitivity tester
  • Full agency compliance with UL 268 and UL 2075

i4 Series Combination CO/Photoelectric Smoke Detector


System Sensor - Data Sheet

i4 Series Combination Carbon Monoxide (CO) / Photoelectric Smoke Detector


System Sensor - Installation and Maintenance Instructions

Related Products...