Features: It can be used in restaurant, tea house, cafe, factory, bank, bar, disco, billiard room, hospital, clinic, nursing home, etc. Wireless, easy to use, no string code. With double-sided tape, it is easy to install and can be directly pasted. With one-touch call function, it can be used with the host. SAW DEVICE air communication special parts are used to ensure signal transmission. Stability: Built-in channel anti-mix function, built-in timing circuit design. Specifications: Condition: Brand New Material: ABS Product features: Product call function can be customized Receiving distance: 1000 meters in the open area, 40-80 meters indoors Product size: Approx.86*86*15mm/3.4*3.4*0.6in Product color: White Flip frequency band: 433MH2/315MHZ Call function: Call cancellation Button: Two buttons Call package: same as all receiving hosts of the brand Use power: use 12V 23A dry battery Ancillary products: Original imported chips Receiving principle: Using aviation-specific transmission frequency Product movement: The number can be changed, it can be reused Weight: Approx.86g/3oz Package List: 1 * Alarm (With Battery) 1 * Double-sided Sticker 1、It can be used in restaurant, tea house, cafe, factory, bank, bar, disco, billiard room, hospital, clinic, nursing home, etc. 2、With double-sided tape, it is easy to install and can be directly pasted. 3、With one-touch call function, it can be used with the host. 4、SAW DEVICE air communication special parts are used to ensure signal transmission. 5、Stability: Built-in channel anti-mix function, built-in timing circuit design.