External Alarm for WatchMate 650, 750, 850 & WatchMate VisionAll WatchMate AIS displays include a built-in alarm. This external alarm is an option if you wish to install a remote alarm elsewhere on-board or to increase the loudness of the built-in alarm.This alarm is very loud. It is designed to be easily panel mounted and can be connected directly to any WatchMate without the need for external relays or other components. By simply rotating the sound output vane you can control the volume level.It is easily configured to make a steady continuous or pulsing tone like a truck backup alarm. It is heavy-duty and very rigidly made. Terminals are via screw down or you can use 6.35mm (1/4") quick disconnects.This alarm is designed to be used with both 12 and 24 VDC systems. It also has reverse polarity protection to prevent damage due to incorrect wiring.Installation details and wiring diagram for WatchMate 850 and Vision.For WatchMate 670 & 750 it is connected differently. In addition to the installation details, please see the WatchMate 670 & 750 wiring diagram for the correct connections.Specifications:Rated voltage: 12-24 VDC (reverse polarity protected)Maximum voltage: 32 VDCMaximum current: 35 mAFrequency: 2.9 kHz (+/- 0.5)Configuration: Makes either a steady or pulsed soundSound pressure: 85 steady, 80 pulsed dBA/30cm (adjustable volume)Pulse rate: 0.8 - 1.2 pulse/secSize: Diameter: 43.5mm (1-3/4"), Height: 34.5mm (1-3/8")Mounting hole: 29mm (1-3/16")