The Characteristic list as follows: 1.Power arbitrary choices: (cell or battery) DC 12 V, 24V, 48V, the exchange of 110 V, 120V, 220V 2. High frequency; 700 Hz - 1700Hz alarm sound very easy to distinguish between noise and the environment, clear, piercing and sharp. 3. Extensive application areas: automobiles, trains, ships, airports, ports, Crossing platform, silver floor, schools, hospitals, residential areas, shopping centers, warehouses, hotels, military units, factory construction, mining, sluice, and other places. 4. Strong compatibility; With smoke detectors, gas gas sensors, infrared sensors, liquid level sensors, timer, anti-theft alarm system, such as the various-connected sensors can also be used alone, which is different from other alarm signals in the high-frequency sound alarm sound source. 5. Several installation forms: horizontal, vertical, activities - and vehicle-mounted, fixed, wall-type, embedded. 6.Design: fashion, unique, innovative, artistic, and easy to integrate into the use of premises, both embellishment and played beautiful scenery