Swiss K31 diopter sights

K31 diopter sights (made by Swiss Products USA) with a Wyss (Switzerland) front sight tunnel W1. The diopter has a Gemann Germany adjustable Aperture 0.8 - 2.2mm with 5-color filter. The W1 front sight tunnel accepts any kind of Anschutz inserts. No modification on the K31 just clamps on the receiver and front sight. Condition like new