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Smoke Detector
A smoke detector is a device that detects smoke, typically as an indicator of fire. Commercial, industrial, and mass residential devices issue a signal to a fire alarm system, while household detectors, known as smoke alarms.

CCTV Camera
Closed Circuit Television, also known by the acronym CCTV, is a private or closed video system.

Barcode Scanner
A barcode scanner is an electronic device for reading printed barcodes. Like a flatbed scanner, it consists of a light source, a lens and a light sensor translating optical impulses into electrical ones.