Schmidt Rubin K31 W-F Diopter K type with Front Tunnel made by Waffenfabrik Bern, Switzerland. 

This is a genuine, no longer manufactured, Swiss Sight, used and approved by the Swiss Government for 300m competition.

Both the "K" tipe W + F K31 Diopter and its front sight tunnel can be mounted on the model K31 Carbine without any modification to the weapon: you can clamp and install them without any additional alterations to the rifle.

Technical characteristics.

The diopter is adjustable for distances of 50m to 600m.

It comes with an eyepiece with a perforated disc that has six sighting holes that could be adjusted for the convenience of the shooter, and measuring

1,0mm

1,2mm

1,4mm

1,6mm

1,8mm

2,0mm.

Windage and elevation adjustments are made with two adjustment screws.

To adjust the elevation for shot too high: turn elevation screw clockwise, while for shot too low you must turn elevation counter-clockwise.

To adjust the windage for shot too left: turn adjuster to the right, otherwise, for shot to right, turn adjuster to the left.

The adjustment screws for both elevation and windage are furnished with click stop graduated lines that represent 2 centimeters each at 300meters distance (so each click corresponds to almost 1/4 MOA).

The sight line distance is 760mm.