All rearsights suffer from backlash on their threads with use and over time which arose originally due to factory engineering. This allows movement of the moving surfaces carrying the iris thread hole and gives rise to its positional movement which directly affects accuracy at each shot - this is made worse by micrometrical movements induced by the action of the rifle which increases this effect, producing erratic and unwanted scores, this is known as 'Backlash'. The new 598S have an innovative new adjustment spindle with internal pressure springs which make for high precision sight adjustment and makes the sight completely 'Backlash' free.
H=hoch means High / UP
T=tief means Low / DOWN