Humminbird 9 20 MSI T MEGA Transom Mount Transducer XM. MEGA SIMEGA DI DualBeam PLUS 20/60/86/55 degrees 200/83/455/800 kHz and 1.2 MHz temperature built-in. For HELIX MEGA Side Imaging units only. Quick and easy installation. Specifications for Humminbird XM 9 20 MSI T MEGA Transom Mount Transducer: Manufacturer: Humminbird Color: Black Features of Humminbird XM 9 20 MSI T MEGA Transom Mount Transducer Mounting Style: Transom Temperature: Yes Package Contents: Humminbird XM 9 20 MSI T MEGA Transom Mount Transducer Humminbird 710262-1: 9 20 MSI T MEGA Transom Mount Transducer XM