Check the listing for details. System Sensor 5621 135 Degree Fixed Temp / Rate-Of-Rise Dual Heat Detector. Condition: New. Listed at 46.99 USD. System Sensor 5621 135 Degree Fixed Temp / Rate-Of-Rise Dual Heat Detector Advanced Security LLC offers UL Alarm Monitoring Services starting at $15.00 per month or DIY Self-Monitoring Services starting at $10.00 per month, NO Contracts, NO Hidden Fees, & NO Activations Fees. Message or visit our website We are an Authorized Alarm DC, Honeywell Home, Resideo, AlarmNet, Ecolink, DSC, Telguard, SecureNet, Uplink, Alula & 2GIG Security Dealer. We only sell Genuine Products, from authorized distributors . Not closeouts or old stock. The System Sensor 5621 135 Degree Fixed Temp / Rate-Of-Rise Dual Heat Detector can accommodate a broad range of applications. Both single and dual circuit models are available for low and high temperature ratings with either fixed temperature or combination fixed temperature rate of rise (ROR) activation. The ROR element of the fixed/ROR models is restorable to accommodate field testing. System Sensor's 5600 series mechanical heat detectors offer a low-cost means for property protection against fire, and for non-life-safety installations where smoke detectors are inappropriate. Main Features: The 5600 series offers a full-line of configurations to accommodate a broad range of applications. To satisfy a variety of installation needs, the 5600 series easily mounts to single-gang and octagonal back boxes The 5600 series provides clear markings on the exterior of the unit to ensure that the proper detector is being used. 135°F or 194°F ratings. Plain housing for residential installations (Model 5601P) Easy-to-use terminal screws A broad range of back box mounting options: Single gang 3.5" and 4" Octagonal 4: square with square to round plaster ring Click here for more System Sensor Products 783863022487