One possible embodiment of the invention could comprise an interlocking device for the adjusting the length of at least one telescopic tow bar leg of a tow bar. The telescopic tow bar leg could comprise an inner bar and outer bar, the inner bar being generally movably received by the outer bar. Movement of an outer bar mounted pawl into engagement with inner bar may lock the inner bar in relationship to the outer bar. A pawl release mechanism may be used to either act directly upon the pawl or to rotate a cam that contacts the pawl. Either action generally causes the at least two surfaces of the pawl to move out of contact with the inner bar's pawl engagement area, thus substantially allowing the inner bar to move relative to the outer bar. This could allow a user to adjust the length of the telescopic leg.