System Sensor 4WTR-B White 4-Wire Photoelectric i3 Series Smoke Detector with Thermal Sensor is a multi-criteria fire detection device designed for conventional fire alarm systems requiring both smoke and heat sensing. Featuring a plug-in i3 design with integrated sounder and relay output, it delivers reliable detection performance with simplified installation and maintenance.

• Photoelectric smoke sensing combined with isolated thermal sensor provides enhanced multi-criteria fire detection accuracy
• Integrated 85 dB sounder and Form C relay output support local alarm signaling and system integration
• Plug-in i3 design with included base enables fast installation using Stop-Drop ’N Lock mounting system
• Drift compensation and smoothing algorithms improve long-term stability and reduce nuisance alarms
• Removable cover and chamber design allows for easier cleaning and simplified maintenance access