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Element coefficients for a normalized symmetrical low-pass filter, having "equal ripple" response in both pass and stop bands, are presented graphically. The coefficients are plotted against the relative selectivity of the filter, with a loss factor as independent parameter. The interval between curves is sufficiently small to permit interpolation with an accuracy of per cent. Frequency and impedance transformations are included to allow the elements of a practical filter to be derived from those of the appropriate normalized design. The loss function corresponding to a particular design is readily formulated in terms of the loss factor above and the appropriate frequencies of zero loss.