Humminbird PiranhaMAX 20 4-Inch Waterproof Fishfinder and Dual-Beam Transducer 60-degree dual-beam sonar covers wider area for fish with better bottom definition and a depth to 600 feet True 4-level grayscale for clear image of bottom, fish and structures on a high-contrast LCD screen Easy one-touch control accesses full set of advanced features Runs on 10-20 volts DC power, with an output of 100 watts RMS Ultra-compact size measures only 4.375 x 6.125 x 3.25 (WxHxD) with gimbal mount