The Samlex SDC-30 converts 24 volt power systems down to 12 volts. Now you can connect your 12 volt CB radio, AM/FM stereo, lights, sonar, depth finder, GPS and other 12v electric devices to your main power supply by using the SDC-30. Use with heavy trucks, earth moving equipment, buses, marine vehicles and more! Current output is 30 amps. The Samlex converters are highly efficient switchmode devices with suitable electronic protections. RoHS compliant.