System Sensor 2WT-B White 2-Wire Photoelectric i3 Series Smoke and Heat Detector with 135F Fixed Thermal Sensor combines photoelectric smoke sensing with a 135°F fixed thermal element for reliable multi-criteria detection in conventional fire alarm systems. Designed for fast installation and simplified maintenance, it delivers intelligent diagnostics and clear visual status indication in commercial and institutional environments.

• Photoelectric smoke sensing combined with 135°F fixed temperature thermal detection for enhanced fire recognition
• 2-wire plug-in design with included mounting base for fast installation and reduced wiring complexity
• Drift compensation and smoothing algorithms reduce nuisance alarms and improve long-term stability
• Wide-angle dual-color LED indicators provide instant visual status (normal, alarm, trouble, maintenance)
• Compatible with multiple back box types including single-gang, octagonal, and 4-square configurations