Any measurable or observable characteristic related to the shape, structure, color, or pattern of the single, three-stranded inter-row filaments that extend obliquely from the tip of one stereocilium to the lateral side of an adjacent taller stereocilium; in the mouse, tip links are already detectable at E17 and persist throughout life; tips links are thought to gate the mechanotransducer channel, are lost from the cell surface after exposure to either calcium chelator BAPTA or lanthanum, and resist degradation by the protease subtilisin.