230 feet far enough to cover every door and window in your house. Each wireless doorbell receiver can pair up to 20 magnetic door alarm sensors and each sensor can add unlimited receivers. One transmitter can pair with several(max 30) receivers, and one receiver can pair with several(max 30) transmitters.
eBay
KERUI M5 32 Songs Wireless PIR Motion Sensor Door Bell Shop Visitor Alert Chime Alarm Burglar Doorbell for Office/Home Security
Aliexpress UK
The Door Stop Alarm is a portable door stopper wedge that doubles as a security alert detection device.
eBay
Mini Wireless Alarm Door Stop Alarm 120dB Great for Home Wedge Shaped Stopper Alert Security System Block Blocking System
Aliexpress UK
3 Wireless PIR Motion Detector with 9V Battery. The host supports up to 30pcs wireless detectors, 8pcs remote key fobs, 4 doorbell buttons. 2 Wireless Remote Key Fobs with 23A 12V Battery. 2 Wireless Door Sensors with 23A 12V Battery.
eBay
Hollarm Wireless Doorbell Set 400M Remote Control Waterproof 433MHz Wireless Alarm Smart Home Welcome Door Bell Chime EU US Plug
Aliexpress UK
eBay
Scare off would-be intruders and alert the neighborhood with this wireless 105 dB indoor/outdoor siren. Loud 105 dB siren makes sure the alarm is heard when a security risk is detected. IP65 weather-resistant design, so the siren can be used indoors...
eufy
Designed for convenience and security, thiswireless pair includes asensor and receiver that communicate instantly — no wiring or internet required. TheDigiteck B1A makesentry awareness effortless. 📡Long Range Wireless Transmission – Up to 100m (line of sight).
eBay
Wireless Keypad Opener Rolling Code 433MHz Remote Control With 12V/24V 2CH Receiver For Automatic Garage Door Swing Sliding Gate
Aliexpress UK
DUAL MODE SELECTION: Switch and alarm mode integrated key, push up is the doorbell, push down is the alarm sound, when not in use, the switch key resets. STRONG DETERRENT: Built-in high-loudness alarm horn, the decibel reaches 120db, making a harsh sound, powerfully deterring thieves.
eBay
Mihome Smart Lock Cylinder Wireless WIFI Zigbee Lock Core Intelligent Encryption Door Lock E-keys Support For Mijia Mi home APP
Aliexpress UK
Play the music you select in music /doorbell mode. It is used directly after receiving, put in battery and adjust angle to avoid false alarm, not suitable for outdoor because of lack of waterproof function.
eBay
5GHz 2.4GHz Wireless WIFI Doorbell 1080P Video Intercom Door Bell with Camera Tuya Smart PIR Motion Detection Home Security Bell
Aliexpress UK
120dB high-pitched continuous siren when it is enabled. Type: Door Stop Alarm. Easy Install: No wiring needed, just put 9v battery in and switch the button on the back to “ON” then it can works. The bottoms are made of synthetic rubber for keep the alarm from slipping.
eBay
Intelligent Wireless Doorbell Home Welcome Doorbell Waterproof 300m Remote Smart Door Bell Chime EU UK US Plug Optional
Aliexpress UK