Transducer manufacturer: Sonic concepts, Custom-made (Model H-246). Transducer Housing: Brass, RF-shielded, MRI-safe, water-tight. Cylindrical Housing dimensions: 38.1 mm outer diameter, 10 mm high. BNC Cable: 50 Ohms, side exit, 6-m length, exits housing on side. Center Frequency: (Fundamental): 500 kHz. Operating band: 400–600 kHz. Environment: MRI-safe, Immersible in water to a depth of 3.5 m, Matching Network: A fundamental resonance mode RF impedance matching network is supplied inside an RF-shielded external enclosure, intended for use with a 50 Ohm RF amplifier.