The Brass Middle Sight Bead fits all Krieghoff K-80 and Zoli ribs, with easy attachment to the front using a single screw-in piece. The mid bead gives you excellent quick alignment with the front sight to the target and is highly visible even in fading light. Easy fitting using soft tip pliers. – Regular size Measures 2.5 mm wide – Large size measures 2.7 mm wide.