The PiranhaMax 153 is one of the small units available for quite an affordable price. This unit is actually very similar to the PiranhaMax 150, only with a slightly different screen. Its display is 4-inch diagonal, 4-level grayscale, with a pixel resolution of 160V X 128H, and backlight.
This unit has a power output of 100 Watts (RMS) / 800 Watts (PTP), and a depth capability of 600 ft., making it ideal for small lakes, ponds and rivers. It has Dual Beam sonar, using two frequency modes: 200 kHz / 20° and 83 kHz / 60°. It also has the FishID+ option, which can be very helpful on a grayscale screen. The standard transducer of this unit is a Transom-type, XNT-9-20-T.