Battery Sensor for Siren 3Monitor battery voltage with the Wireless Battery Sensor, and never worry about a dead battery again. Attach the Battery Connector to one of the boat’s batteries and plug the other end into the Wireless Module. Link the module to the Siren 3 Pro and receive alerts if the battery voltage exceeds or drops below a preset level. Ideal for monitoring multiple batteries on a boat.Features:Compatible with Siren 3 Pro onlyIncludes: Wireless Sensor Module and Battery Connector with 3 feet of wire