It works by detecting the unique frequency of the ultrasonic waves emitted by potential intruders, triggering your alarm system to sound an alert and scare off any would-be thieves.
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21 Inch Subwoofer Amp F1211 Speaker Audio System Sound pa Speaker pa System Outdoor Concert Sound System Professional Sound
Aliexpress UK
School & Factory Bell Systems. Supplied with 1 x 6" 240v Bell, sound level 95dB. Mains connection cable not supplied.
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ULTIMEA 7.1 Surround Soundbar, 3D Virtual Surround Sound System with Subwoofer,2 Rear Speakers, Home Theater TV Speakers,Black
Aliexpress UK
Material: 5.3 oz/yd², Dark Heather, Graphite Heather, Heather Navy, Heather Red, Tweed (50% cotton, 50% polyester); Sport Grey, Antique Irish Green, Antique Orange, Antique Sapphire (90% Cotton/10% polyester), Ash (99% Cotton/ 1% Polyester), All Others (100% cotton).
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1000W high-power caixa de som bluetooth home TV living room KTV Bluetooth speaker surround sound subwoofer theater sound system
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RC Truck Sound System Adapter Module Cables Suitable For NOOXION And Fury Bear Sound System Light System Adapter Kits DIY Parts
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ULTIMEA 7.1 Surround Sound System Sound bar for TV with Dolby Atmos&APP Control, Home Cinema Bluetooth Speaker with Subwoofer
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RCF HDL 20-A active line array dual 10 inch speaker dj speaker set system speakers audio system sound sound bar with subwoofer
Aliexpress UK
1000W high-power home TV living room KTV Bluetooth speaker subwoofer surround 5.1 cinema sound system caixa de som Bluetooth
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3000W Portable Bluetooth Speaker Sub woofer Heavy Bass Sound System For Party With Microphone, Remote, FM, TWS, AUX, USB, LED
Aliexpress UK