Isolator modules protect an addressable loop from a single-point failure. A short circuit anywhere on a loop can take the entire loop offline; isolators segment it, so a fault is confined between two isolators and the rest of the loop keeps reporting.
They come as standalone modules and built into detector bases. Placement is a design decision — more isolators mean smaller affected segments and a higher device count — and many codes set a maximum number of devices that may be lost to one fault, which effectively sets the spacing.
Isolators are loop-specific: match the module to the panel protocol.

Edwards
Edwards SIGI-CT1I 1 Circuit Input Module with Isolator, Edwards
Sale price$53.55
Regular price$64.26
Not in stock - available on backorder - lead time on request
Edwards
Edwards SIGI-CRI Control Relay with Isolator, Edwards
Sale price$53.45
Regular price$64.14
Not in stock - available on backorder - lead time on request
Edwards
Edwards SIGI-CC2I Dual Input Signal Module with Isolator, Edwards
Sale price$89.75
Regular price$107.70
Not in stock - available on backorder - lead time on request
Edwards
Edwards SIGI-CC2AI Dual Input Signal Module Class a with Isolator, Edwards
Sale price$125.30
Regular price$150.36
Not in stock - available on backorder - lead time on request
Edwards
Edwards SIGI-CC1SI Single Input Signal Module, Synchronization, with Isolator, Edwards
Sale price$74.15
Regular price$88.98
Not in stock - available on backorder - lead time on request
Edwards
Edwards SIGI-CC1I Single Input Signal Module with Isolator
Sale price$52.50
Regular price$63.00
Not in stock - available on backorder - lead time on request
Apollo
Apollo 55000-847APO Apollo XP95 Input / Output Unit with Isolator
Sale price$77.10
Regular price$92.52
Not in stock - available on backorder - lead time on request
Notifier
Notifier WWL-RC-I02 Body Colour - Red Flash - White Lens - Clear Isolator - Yes Wall VAD - Wall-mounted, Addressable, with Visual Alarm Device (VAD)
Sale price$136.70
Regular price$164.04
Not in stock - available on backorder - lead time on request
Notifier
Notifier WWL-PC-I02 Body Colour - White Flash - White Lens - Clear Isolator - Yes Wall VAD - Wall-mounted, Addressable, with Visual Alarm Device
Sale price$134.65
Regular price$161.58
Not in stock - available on backorder - lead time on request
Notifier
Notifier WRL-RC-I02 Body Colour - Red Flash - Red Lens - Clear Isolator - Yes Wall VAD - Wall-mounted, Addressable, with Visual Alarm Device (VAD)
Sale price$134.65
Regular price$161.58
Not in stock - available on backorder - lead time on request
Notifier
Notifier WRL-PC-I02 Body Colour - White Flash - Red Lens - Clear Isolator - Yes Wall VAD - Wall-mounted, Addressable, with Visual Alarm Device (VAD)
Sale price$137.70
Regular price$165.24
Not in stock - available on backorder - lead time on request
Notifier
Notifier NFX-MM1M Addressable Mini-module Monitor (input) Module - Opal Compatible Without Isolator
Sale price$95.60
Regular price$114.72
Not in stock - available on backorder - lead time on request
Notifier
Notifier NFSTI-OPT Notifier Self Test Optical Detector with Isolator
Sale price$98.25
Regular price$117.90
Not in stock - available on backorder - lead time on request
Notifier
Notifier M701E Analogue Addressable SINGLE OUTPUT Control Module Complete with End of Line Resistor, Plug-in Screw Connections, Direct Decade Address
Sale price$106.90
Regular price$128.28
Not in stock - available on backorder - lead time on request
Notifier
Notifier BST-PC-I02 Body Colour - White Flash - Red Lens - Clear Isolator - Yes Base VID - Addressable Loop Powered Visual Indicating Device (VID).
Sale price$112.00
Regular price$134.40
Not in stock - available on backorder - lead time on request
Notifier
Notifier ISO-XA SLC Loop Isolator Module. Isolates Against Short Circuits on the SLC
Sale price$53.00
Regular price$63.60
Not in stock - available on backorder - lead time on request
Det-Tronics
Det-Tronics 000515-558 APOLLO ISOLATOR BASE, NA
Sale price$23.80
Regular price$28.56
Not in stock - available on backorder - lead time on request
Det-Tronics
Det-Tronics 000515-557 APOLLO ISOLATOR, NA
Sale price$116.55
Regular price$139.86
Not in stock - available on backorder - lead time on request
Det-Tronics
Det-Tronics 000515-519 APOLLO INTELLIGENT ISOLATOR BA
Sale price$11.90
Regular price$14.28
Not in stock - available on backorder - lead time on request
Det-Tronics
Det-Tronics 000515-512 APOLLO MANUAL CALL W/ISOLATOR
Sale price$172.45
Regular price$206.94
Not in stock - available on backorder - lead time on request
Det-Tronics
Det-Tronics 000515-509 APOLLO I/O UNIT W/ ISOLATOR
Sale price$381.80
Regular price$458.16
Not in stock - available on backorder - lead time on request
Det-Tronics
Det-Tronics 000515-508 APOLLO INTELLIGENT ISOLATOR
Sale price$83.25
Regular price$99.90
Not in stock - available on backorder - lead time on request
Apollo
Apollo 55000-802APO XP95 DIN-Rail Isolator - Dual Channel
Sale price$73.10
Regular price$87.72
Not in stock - available on backorder - lead time on request