Gehmann Tower Rear Sight Ultra-compact design means a large field of view while in the shooting position to observe wind flags Both-sided windage adjustment knobs ensure comfortable usage for left- or right-handed shooters Strong springs are used to guarantee maximum repetition accuracy per click Thread tunnel (M9,5x1) enables the shooter to attach any irises and anti-glare tubes or other accessories 20 wear-free balls made of stainless steel inside the adjustment knobs for clear but sensible adjustment The bullet shift per click is: 0.50mm at 10m (distance between rear sight and front sight = 65cm) 0.45mm at 10m (distance between rear sight and front sight = 80cm) 2.70mm at 50m (distance between rear sight and front sight = 65cm) 2.20mm at 50m (distance between rear sight and front sight = 80cm)