Simplex, now part of Johnson Controls, is one of the most widely installed fire alarm brands in North America. Simplex systems are found in hospitals, universities, airports, high rises and industrial plants, and they are maintained for decades rather than replaced. That long service life is exactly why the parts are hard to find, and it is what this collection is aimed at.
With well over a thousand Simplex line items in stock, we cover:
- Simplex smoke detectors and sensors - photoelectric, heat, combination photoelectric and heat, and carbon monoxide sensors, plus replacement cartridges
- Sensor bases, including standard, sounder and relay bases
- Duct detectors, duct housings and duct covers
- Addressable modules - individual addressable modules, zone adapter modules, relay modules and NAC extenders
- Single and double action pull stations, break rods and station keys
- Horns, strobes, horn strobes and speaker strobes, wall and ceiling mount
- Device covers, cover plates and trim in red and white
Much of what we hold is discontinued or superseded Simplex stock kept specifically for existing installations. If a part is not listed, send the number through our quote page.

Simplex
Simplex 4903-9148 Speaker/Visible Notification Appliance, 30 cd Xenon Strobe, Red, Horizontal Wall Mount
Sale price$106.00
Regular price$127.20
Contact Us for Alternatives
Simplex
Simplex 49SVC-WWFIRE TrueAlert ES Speaker Visible Cover, Wall, White, FIRE
Sale price$7.75
Regular price$9.30
In Stock
Simplex
Simplex 4098-9734 TrueAlarm High Temperature Heat Sensor, White
Sale price$20.15
Regular price$24.18
In Stock
Simplex
Simplex 49WPBB-AVVOWW Back Box, Wall Surface-Mounted
Sale price$16.75
Regular price$20.10
In Stock
Simplex
Simplex 4098-5611 Heat Detector, 135F Fixed Temperature Only, for Two-Wire or Four-Wire Bases
Sale price$41.60
Regular price$49.92
In Stock
Simplex
Simplex 565-028 8 Amp Expansion Power Supply Board, 4100/4100+/UT
Sale price$144.75
Regular price$173.70
In Stock
Simplex
Simplex 4903-9252 Audio/Visible Notification Appliance Wall-Mount
Sale price$238.50
Regular price$286.20
Contact Us for Alternatives
Simplex
Simplex 4906-9202 TrueAlert Multi-Candela Addressable Strobe
Sale price$69.90
Regular price$83.88
In Stock
Simplex
Simplex 2081-9279 110 Ah Sealed Lead Acid Battery
Sale price$477.80
Regular price$573.36
In Stock
Simplex
Simplex 4100-5401 ES-PS Fire Alarm Power Supply and Battery Charger, 120 to 240 VAC, 4100ES
Sale price$675.35
Regular price$810.42
Not in stock - available on backorder - lead time on request
Simplex
Simplex 4100-1272 Expansion Phone Controller
Sale price$325.20
Regular price$390.24
In Stock
Simplex
Simplex 2081-9028 Isolated Loop Circuit Protector (ILCP)
Sale price$61.30
Regular price$73.56
In Stock
Simplex
Simplex 4099-9005 Addressable Manual Pull Station, Double Action Breakglass
Sale price$50.50
Regular price$60.60
In Stock
Simplex
Simplex 6334-9125 Digital 2.5" Red LED, 120 VAC
Sale price$540.20
Regular price$648.24
In Stock









