This sonar sensor is a great accessory for your fish finder. Features: Wireless sonar sensor for LUCKY fish finders. 45m depth range. 90-degree beam angle, 125KHz sonar frequency. Durable plastic construction with watertight seal cover and seal ring. Runs on a replaceable CR2032 battery. Special holes allow you to tie your fishing line onto it, easy to cast. Note: D refers to Depth, D+T refers to Depth and Temperature. D transducer is for basic fish finders: FFW1108-1, FFCW1108-1. D+T transducer is for most of the LUCKY fish finders, such as FFW718, FF518. Specifications: Material: Plastic. Model: D / D+T (optional). Depth Range: 45m / 147ft. Beam Angle: 90°. Sonar Frequency: 125KHz. Dimension: 7.8 x 5.5cm / 3.1 x 2.2in. Weight: 45g / 1.6oz. Package List: 1 x Sonar Sensor for Fish Finder