117WR-3 Double Handle Transducer Wrench, Transducer wrenches are available for all bronze low profile transducers. They are used to facilitate holding of the transducer and tightening of the hull nut. Wrenches are constructed of 3/16" thick mild steel. They can easily be bent or modified to accommodate challenging installation locations. For use with: B117, B150, B744V, B744VL, B765C, and SS555.