Digital Sounder Module with HDFI (High Definition Fish Imaging) Technology. hsb2 and C-Series compatible "black box" fishfinder DSM250 Echo Sounder Features Dual frequency operation (200/50 kHz) 1000 or 600 watt available output power depending choice of transducer HDFI Auto Adaptive Gain control (no adjustment required) Patent Pending Digitally Adaptive Transmitter Receiver with infinite receiver bandwidth settings and digital filter A-Scope (Real-Time Display): Split second real time representation of fish and bottom features passing through the beam of your transducer right now, the history of your A-Scope is represented in the standard sounder image scrolling across your screen. Zoom Display: Auto or manual zoom magnification of any part of the 200 or 50 kHz fishfinder screen image, (X 2, X4 or X6 magnification). Bottom Lock: The bottom lock feature, shows the bottom as a straight line, in order to help you detect fish close to the bottom and remove wave action from the fishfinder image. Full Screen or Split screen display: All fishfinder display functions can be shown in full page screen mode, or split horizontally or vertically with other functions, such as chartplotter, waypoint 3D steering indicator, large character depth/temp/speed digit readout, etc. White Line: The White line feature helps distinguish between fish and the bottom, when fish are swimming close to the bottom. Depth Temperature Graph: Plots depth and temperature changes over time. High performance transducer required. $649.00 Please call 1-908-642-8579 or e-mail us at NCTackle@aol.com with any questions. Thank you for shopping with us! FREE SHIPPING ON ORDERS OVER $250!