A bracket for use on an ultrasound transducer to releasably mount at least one 3D tracking sensor on the transducer. The fuel cell includes an elongate member including opposing first and second ends and defining an interior cathode portion and an exterior anode portion. The first particles comprise a magnesium oxysulfate compound. Circuits connect these primary and secondary winding in parallel and serial combustion to provide a transformer having the desired turns ratio. The aqueous emulsion can be used to prepare a hybrid polyolefin-polyurethane dispersion useful, inter alia, as an adhesion-promoting coating for polymers such as the polyolefins.