Abstract: Regarding a sighting telescope reversing system which comprises a guide casing fitted with a linear cam slot, further an external casing fitted with an external cam slot and fixed in the axial direction while rotatably supported on the guide casing, a mount holding a lens element and fitted with a guide pin passing through the linear cam slot as well as through the external cam slot, the present invention stipulates that the guide pin be fitted with a first and a second collar, both collars resting on a common shaft, the first collar being displaceable within the external cam slot and the second collar being displaceable within the linear cam slot.