NB-326-SH-2 Conventional Combine (Optical Smoke+Heat) Detector come with an photoelectric smoke detector and a fixed temprature heat dedector. They offer a general purpose protection of a rapid fire and a smoldering fire incident.  

Features：
● 2 or 4 wire models
● Dual LEDs for 360°visibility
● Advanced detection and discrimination algorithms
● Easy installation and maintenance
● Sleek low-profile housing design
● Durable sensor head, no need for replacement
● SMD circuit board design-satisfactory quality and reliability guaranteed
● Integrated heat detector for NB326-H-2 and NB326-H-4 models
● Five-year limited warranty
● N/C (normal/close)-N/O (normal/open)selectable relay output
● AR (Auto Reset) function for security systems (optional for 4 wire models)
● Sensor base option: standard and Shottky Diode