Siren Marine Siren 3 Main Device [6X885B130000]Siren 3 Main Device Designed with small to medium boats in mind, the Siren 3 offers immense value at an affordable price. Together with the Siren Connected Boat Mobile App, our Smart Boat Monitoring System puts your boat in the palm of your hand 24 7. Install the Siren 3 on your boat to monitor and track multiple critical systems such as battery levels, bilge pump activity, engine performance, temperature, location, and more, all right on the App*.