New 10 x RC-33 NC Wired Door Contact Sensor Alarm Magnet Reed Switch
$12.78
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Sensors & Motion Detectors
Motion, door/window and glass-break sensors are the trip-wires of a security system. Check what hub or panel they pair with (many are brand-specific and won't mix), wired vs wireless, and battery life for wireless units. For motion sensors, pet-immune designs avoid false alarms. Buying spare or used sensors is fine — just confirm the protocol and that they're compatible with your system.
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Motion Sensor DC 5V 24V Light Switch Movement Detector Automatic PIR Sen A
$10.11
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
WiFi Water Level Monitor Alarm Float Sensor Battery
$154.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Ceiling Mount 360 degree PIR Occupancy Motion 10A,Neutral Wire Required
$32.45
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Wireless Motion Sensor Plug Kits,No-Wire Mini PIR Sensor Motion Sensor+plug
$41.12
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Low-Cost Water Leak Alarm Flood Level Overflow Detector Sensor Home Security
$6.18
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SimpliSafe SimpliCam Model SSCM1 Black BRAND NEW IN BOX
$34.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
WiFi Water Level Float Sensor Monitor Alarm
$154.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
ADT SCN# 875938 RX7 Indoor Sounder Alarm
$23.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Simplisafe Motion Sensors Gen 3 White 3 (three} BRAND NEW
$35.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
WiFi Water Level Monitor Alarm Float Sensor Battery
$154.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
1pc Driveway Alarm Infrared Motion Sensor Home Garage Alert Security System
$19.15
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
WiFi Water Level Monitor Alarm Float Sensor Battery
$154.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
AC100-240V Motion Sensor Switch PIR Infrared Auto On/Off for LED Lights White
$12.23
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
4 Modes Solar Motion Sensor Alarm 129dB Outdoor Siren With 13 Sounds For Farm
$25.10
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Compact Motion Activated Light Switch - Ground Wire Needed, Easy Installation
$33.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Black 24.125GHz Human Inductive Motion Microwave Radar Sensor For Automatic Door
$19.31
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Greencycle Door Buzzer for Business Entry, Motion Sensor, Motion Sensor Door Ala
$58.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Automatic Water Leak Detector with Sensors and Shut-off Valve
$78.59
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Honeywell Aurora Pet Immune PIR Motion Sensor
$15.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE White PIR Motion Sensor Wall Switch AC100-240V for Downlights & Ceiling Lights
$11.98$13.16
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE 3-5m Automatic Body Infrared PIR Motion Sensor Detector Switch For LED light C
$9.90$10.88
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
WiFi Water Level Monitor Alarm Float Sensor Battery
$154.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
20M Single Beam Detector Alarm Photoelectric Infrared Laser Sensor Anti Theft D
$15.24
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Water Leak Detector WiFi Alarm Float Sensor Battery
$154.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE New Low-Cost Water Leak Alarm Flood Level Overflow Detector Sensor Security
$10.08$11.08
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
3 Packs 12 V 24 V PIR Sensor Adjustable LED c Black Infrared Motion Detector ...
$18.83
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
130dB Solar Motion Sensor Alarm: Custom Alerts & Wildlife Deterrence Solution
$51.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE 5-24V USB Port Detector Infrared PIR Motion Sensor Switch For Led Light Strip ff
$10.80$11.87
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Shelly Motion 2 Wi-Fi Smart Home Motion Sensor - White (New, Open Box)
$34.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Lot of 7 Honeywell Resideo SIXCTA Door/Window Contact Wireless Sensor ADT
$99.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Qty5 Interlogix Simon XTi-5, Pet Immune Sensor, Micro KeyFob, Door/Window Sensor
$480.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Lot Of 2 SimpliSafe Glassbreak Detector Sensor GB1000 (Gen 1) - NEW
$29.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE Solar Outdoor Motion Sensor Alarm with Dog Bark Sound, 130dB Loud Noise Maker, 3
$48.59$53.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Honeywell Water Leak Detector New White WHLDT100 Alarm Audible Alert Detection
$25.95
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Hidden Camera Detector RF Scanner & GPS Tracker Detector for Travel Security
$78.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Flood Buzz Blue Water Leak Alarm Siren 110 DB Sensor Battery New
$7.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Ring Smart Lighting Motion Senor Bridge Is Required White New
$24.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
NEW Lot x2 Honeywell Home 5800PIR-RES Entry-Level Wireless PIR Motion Sensor Pet
$101.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
U.S. Patrol Driveway Patrol Garage Motion Sensor Security System - White
$18.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
ReX-10 Sound Detector Barking Dog Alarm
$24.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Bosch b8512g bundle - NEW - excellent condition
$1,000.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
WiFi Water Level Monitor Alarm Float Sensor Battery
$154.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Water Leak Detector WiFi Alarm Float Sensor Battery
$154.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
WiFi Water Level Monitor Alarm Float Sensor Battery
$139.66
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
WiFi Water Level Monitor Alarm Float Sensor Battery
$154.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE 2pcs 180° PIR Motion Sensor Switch infrared wall mount switch 50/60Hz 110-240V
$13.50$14.84
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Long-Range WiFi Water Leak Detector Kit, 2000ft, SMS Alerts, 105dB Alarm, 5-Year
$125.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.