The Kahlenberg Model Z-320-SC Self Contained Horn represents a new concept in sound signaling for vessels over 75 meters in length. Using an internal, direct drive air source, this new horn is pneumatic in nature but requires no external compressed air source. Only one low amperage A.C. single phase or three phase electrical connection is required for power. Completely contained in a thermostatically controlled, heated, IP-56 enclosure, the Z-320-SC offers a new standard for reliability and longevity in harsh marine environments, previously only matched by pneumatic horns that require an external air source. The Z-320-SC utilizes a special motor controller, Kahlenberg Model M-66, for use with 50 Hz A.C. power applications.