312/2011 - Item 1: Article (so-called ‘ultrasonic transmitter’) consisting of a piezo- electric element in the form of a ceramic disc to which a metal membrane with a radially oriented cone is attached. The whole is fixed to a base plate and is fitted into a plastic casing with connecting pins. Alternating current causes the piezo- electric element to oscillate, creating ultrasonic waves (inaudible to the human ear) that are transmitted through the air. The article thus converts electrical signals into ult - The Trade Hub