A weather radio service is a public broadcast service dedicated to airing continuous weather reports. In most locations, it requires a specially-designed radio capable of receiving "weather band" frequencies - when tuned to one of these channels, it receives a radio station that broadcasts both routine and emergency weather information. Some weather radio receivers are equipped with a standby alerting function - if the radio is off or tuned to another band and a severe weather bulletin is transmitted, it can automatically sound an alarm and/or switch to a pre-tuned weather channel for emergency weather information.