Abstract: The opening of a sliding shackle permits removal of a stack of individual dial type tumbler rings each may possess a number of individual peripherally disposed indicia plates which are removable from each tumbler ring so removed from the body of the padlock. Each tumbler is keyed to permit opening of the lugged shackle in only one rotational orientation of each tumbler. The indicia plates may be interchanged either with others already on that tumbler, another tumbler, or with other indicia plates altogether. Alphabetic as opposed to numeric indicia are suggested, either fixed directly to the tumbler rings or upon separate indicia plates, of which a large supply may be provided together with the padlock so that a large number of letter combinations are available for the padlock opening combination code which may be set by the owner to a desired code word.