A connecting piece for connecting a wiper arm to a wiper blade is proposed, which includes yielding regions, so that wiper arms of the most various sizes can be received. The filter is applied to individual mass chromatograms, plots of ion abundance versus retention time for each detected mass-to-charge ratio, and the filtered chromatograms are combined to form a filtered total ion current chromatogram. One fitting includes at least two threads to provide a more secure fitting able to withstand higher injection pressures. The method also includes applying the generated baseband transmit signal to the direct microphone audio input to thereby transmit a digitally encoded RF TX signal having a constant envelope and using the analog FM transceiver to receive a digitally encoded RF RX signal with a constant envelope and to generate a baseband receive signal using the digitally encoded RF RX signal.