Electric signal horn, complete with loudspeaker, built-in diaphragm control panel and electronic controller. New ultrasonic heating system provides improved acoustic diaphragm performance. Meets COLREG 1972 IMO Class IV international regulations and is approved by RINA, LLOYD'S REGISTER MCA, BUREAU VERITAS, NMMA and BSH. Automatic fog signal function. Includes mounting kit. Volume >130 /698 Hz. Horn material phenolic resin.