Resideo SIXCTA Two-Way Wireless Door and Window Alarm Contact Sensor - White
$23.99
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.
Solar Motion Sensor Siren 6 Pack Outdoor 129db Alarm
$141.09
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
3 Pack Zigbee Vibration Sensor 110dB Alarm SmartThings Echo Hub Compatible
$70.39
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Qualirey Solar Sound and Light Alarm Motion Sensor 129db 6 Pack
$105.84
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Occupancy Motion Sensor Light Switch, PIR Infrared Motion Activated Wall Swit...
$22.81
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Water Leak Starter Kit: Hub + 6 Leak Sensor 4 (105 dB Siren), LoRa Long-Range...
$128.22
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Water Leak Starter Kit: Hub + 2 Leak Sensor 1 (Silent), LoRa Long-Range, App/...
$53.20
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE Smart WiFi Door Sensor - Wireless Alerts, Compatible with Alexa/Google - 4-Pack
$73.48$97.97
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
1PCS KEYENCE IV-G500CA Vision Sensor New
$477.94
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SYLVANIA 45030-0 ELSC-DLH-TVLAMP / BUS ELOGIC DAYLIGHT HARVESTING SENSOR CONTROL
$29.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Qualirey Solar Sound and Light Alarm Motion Sensor 129db 6 Pack
$105.84
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
1PCS KEYENCE IV-G500CA Vision Sensor New
$477.96
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Energy-Saving PIR Body Infrared Motion Sensor Switch - 30W Power and Adjustable
$14.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
1PCS KEYENCE IV-G500CA Vision Sensor New
$477.93
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
1PCS KEYENCE IV-G500CA Vision Sensor New
$477.98
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
1PCS KEYENCE IV-G500CA Vision Sensor New
$477.98
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE Security Wireless Mini Door Window Contact SZ-DWS08N-CZ3 Zigbee Sercomm NEW
$4.21$4.95
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Mini DC12V LED PIR Infrared Motion Hot Sensor Corridor Detector Switch Pratical
$9.20
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Zenith Heath Reflex Wireless Supervised Home Protection Alarm System Door Sensor
$44.95
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
GoveeLife Smart CO2 Monitor H5140 Wi-Fi Bluetooth Digital Clock Black Indoor
$39.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE 2pcs RC33 NC Recessed Wire Door Contact Sensor Alarm Magnetic Reed Switch
$12.58$13.24
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
MIER DRIVE-ALERT VEHICLE DETECTION SYSTEM MODEL DA-500 / 100' CABLE IS NEW
$155.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Weather-Resistant Outdoor Lighting Sensor for 3" Post Fixtures - Bronze Finish
$17.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Honeywell SIXMINICT Door/Window Sensor (New/Sealed)
$24.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Sump Pump Water Alarm Waterproof Control Panel Septic Tank Water Detector Alarm
$139.98
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
ClareOne CLR-C1-RCDW Recessed Door/Window Sensor - New Open Box
$18.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE Flexible 3.5mm Type Water Leakage Alarm Detector Water Sensory Detection
$12.31$14.15
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Effortless Installation E26/E27 PIR Motion Sensor Light Socket for Indoor Use
$12.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Adjustable Motion Sensor Light Socket - Perfect Solution for Basements & Garages
$14.99
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 zz
$15.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SimpliSafe FS3 Wireless FREEZE Sensor Temperature Detector Indoor White NEW
$18.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
ELK Products ELK-M1DBHR M1 Active RS-485 Data Bus Hub Retrofit NIB
$57.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE 12x GE Sentrol 1032-N Magnetic Contacts Alarm Door Window Reed Switch Sensor
$33.74$44.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
HomeKit Motion Sensor, Temperature, Humidity, ONVIS SMS1, Works with Apple Home
$19.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
GE Choice Alert Wireless Alarm Kit (Model 45171)
$39.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE 4x Sentrol 1032 Magnetic Door Window Contact Reed Switch Alarm Sensor
$18.74$24.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Motion Sensor Light Control Heath Zenith Light Fixture With Infrared Sensors NOS
$20.32
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Legrand Wattstopper UT-305-3 Wired Ultrasonic Occupancy Sensor, White
$97.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Legrand Wattstopper UT-305-3 Ultrasonic Occupancy Sensor, White, Indoor
$50.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Modified Sine Wave Inverter, 1500W, DC 12V to AC 120V Power Inverter with 2 AC O
$153.87
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Defiant Home Security NEW Door Window Alarm 1001-090-100 2 Settings Chime Siren
$12.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Honeywell IS3050 Passive Infrared Motion Sensor With Box
$29.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
ELK-6051 Wireless CO Sensor Two-Way Wireless EXP 08/2030
$135.00
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
WiFi Door Window Sensor Magnetic Alarm Smart Home Security Burglar Alert
$35.02
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE 125dB Motion Sensor Alarm with Remote Control
$34.49$45.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
Heath Zenith SL-5407-BZ-A Replacement 180 Degree Motion Sensor Open box
$19.95
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE (G) ADT Qolsys IQ Remote 7" Touchscreen Panel QW9104-840 w/ Power Adapter
$110.49$129.99
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.
SALE (G) Qolsys IQ Panel 2 Security System QS9201-1208-840 Panel Only
$106.22$124.96
View on eBay
Affiliate link — we may earn a commission, at no extra cost to you. Read our affiliate disclosure.