Echonautics Hydrodynamic Fairing Block f/CB101 Series Transducers [K10TDD001A]Hydrodynamic Fairing Block for CB101 Series Transducers Echonautics fairing blocks are made for the thru hull installation of traditional stem transducers. A fairing block is recommended for the installation of any traditional stem transducers to the vessel's hull to protect the transducer and guarantee excellent performance while the vessel is underway. The fairing block helps to ensure a bubble free flow of water across the face of the transducer.