Review on 🔒 Enhanced Safety: SYSTEM SENSOR CO1224T 12/24 Volt C02 Carbon Monoxide Detector with RealTest Technology by Lee Wilson

Still fresh from the factory so the shelf life before replacement is about 10 years and the "about 10 years" problem at the end of the signal life can be even then expected. Excellent value for money and quality. An ideal replacement for the short-lived Costar 12-24 SIR detector, plus it's easier to connect. Keep in mind that this applies to DC, not AC. Note that while this sends an alarm to your panel with just a 4-wire connection, it also doesn't send an end-of-life signal to your panel (just flashing red at this point) unless you patch add a resistance that does not included; The type of resistor depends on your panel. The instructions include a warning that this additional wiring is required by the rules.