Use for air defense, civil defense alarm system; alarm system for mine, blasting, prisons, reservoirs, power station, substation, airport, police and military bases; for earthquake, tsunami, flood, flood control and disaster relief, mudslides, landslides, fires, typhoons, minefields, forest fire disaster alarm sound; fire or emergency alarm system in factories, schools, wharf, warehouse, public buildings, commercial areas, residential areas, port sand other places.