Amazon.com Product Description: The Humminbird XFM 9 20 Plastic Flush-Mount Thru-Hull Transducer is an economical alternative to bronze transducers, and works with thinner hulls such as aluminum. Constructed with an internal, steel sleeve that provides extra reinforcement, this thru-hull transducer is not recommended for trailered boats, and Humminbird recommends you have it professionally installed due to the fact that it requires a hole be drilled in the hull. The XFM 9 20 is a dual-beam, flush-mount transducer with 20-, and 60-degree beam angles and operating frequencies of 200 kHz and 83 kHz. This unit has a diameter of three inches, with a 0.2-inch below-hull depth and a shaft diameter of two inches. The Humminbird XFM 9 20 comes with a 30-foot connecting cable and all the necessary mounting hardware, and doesn't require a fairing block. The XFM 9 20 is compatible with Humminbird's; Matrix 12, Matrix 15, Matrix 17, Matrix 27, Matrix 67, Matrix 77, Matrix 87, Matrix 97, 727, 737, 767, 777C2, 787C2, 323, 343, 363, 383, 141, Piranha Max 10, Piranha Max 15, Piranha Max 20, 931C, 937C, 515, 525, 535, 565, 585, and HDR610 sonar systems. This item is backed by Humminbird's one-year limited warranty.
