DSM30 HD Digital Sounder Module Digital Sounder Module adds HD Digital technology to Raymarine E-Series and C-Series multifunction displays 600 Watt operation Dual frequency 50/200 kHz Patented Raymarine HD Digital sounder technology Integration Capabilities E-Series SeaTalk hs network integration (optional SeaTalk hs crossover coupler or SeaTalk hs Network Switch is required) C-Series integration hsb2 networking compatible with "Plus" series radars, chartplotters and fishfinders The DSM30 is designed for 12V DC electrical systems only. For 24V DC systems, please use the DSM