An orientation apparatus for a tibial resection guide comprising or consisting of a probing device having: - a helical-shaped or gear-rack shaped adjustment element , - a feeler which is held on the adjustment element , - a helical-wheel shaped or gear-shaped setting element which is engaged with or coupled to the adjustment element in order to move the feeler via the adjustment element by manual actuation of the setting element , - a scale carrier coupled to the feeler or the adjustment element and extending along the adjustment element , wherein the scale carrier indicates a current position of the feeler , preferably with respect to the setting element , with reference to a marking on the setting element , on the feeler or on the adjustment element , - at least one first latch or stop member and - at least one second latch or stop member , - wherein - the first latch or stop member and/or the second latch or stop member is spring-elasticly yielding or mounted in a spring-elasticly yielding manner, so that - the first and the second latch or stop member , upon actuation of the setting element in a specific relative rotational position or within a specific relative position range between the scale carrier and the setting element , the first latch or stop member and/or the second latch or stop member deflects the respective other stop member in a spring-elastic manner, and in that - upon further actuation of the setting element , the first and/or second stop member springs back, preferably abruptly, into a latch or stop engagement with each other, characterized in that - the at least one first latch or stop member is formed on the setting element , and the at least one second latch or stop member is formed on the scale carrier or is formed by the scale carrier . - a helical-shaped or gear-rack shaped adjustment element , - a feeler which is held on the adjustment element , - a helical-wheel shaped or gear-shaped setting element which is engaged with or coupled to the adjustment element in order to move the feeler via the adjustment element by manual actuation of the setting element , - a scale carrier coupled to the feeler or the adjustment element and extending along the adjustment element , wherein the scale carrier indicates a current position of the feeler , preferably with respect to the setting element , with reference to a marking on the setting element , on the feeler or on the adjustment element , - at least one first latch or stop member and - at least one second latch or stop member , - wherein - the first latch or stop member and/or the second latch or stop member is spring-elasticly yielding or mounted in a spring-elasticly yielding manner, so that - the first and the second latch or stop member , upon actuation of the setting element in a specific relative rotational position or within a specific relative position range between the scale carrier and the setting element , the first latch or stop member and/or the second latch or stop member deflects the respective other stop member in a spring-elastic manner, and in that - upon further actuation of the setting element , the first and/or second stop member springs back, preferably abruptly, into a latch or stop engagement with each other, characterized in that - the at least one first latch or stop member is formed on the setting element , and the at least one second latch or stop member is formed on the scale carrier or is formed by the scale carrier . <EOS>