Humminbird XSO 9 20 T Stick-On Transducer Super-easy installation, and improved high-speed reading versus transom mount transducers Single-, or dual-beam use with 20-, and 60-degree beam angles and operating frequencies of 200 kHz and 83 kHz Includes a connecting cable, and the required heavy-duty two-sided 3M installation tape Compatible with many of Humminbird's Piranha, Matrix and numbered series sonar systems Doesn't require any holes in your hull, and is backed by manufacturer's one-year limited warranty