Humminbird XTH 9 DB 74 P Plastic Thru-Hull Transducer Dual Beam transducer 200/74 degree Used for ONIX and ION Series at 200/50 kHz Temperature included for ION ONIX Series Humminbird Limited Warranty Thru-hull transducer, works with thinner hulls, while internal, steel sleeve provides extra reinforcement Dual-beam transducer with 20-, and 74-degree beam angles and operating frequencies of 200 kHz and 50 kHz Not recommended for trailered boats, and professional installation recommended Compatible with, and designed for Humminbird 931C DF and 937C DF sonar systems Includes fairing block, and is backed by manufacturer's one-year limited warranty