With this solution, one part (the clamping sleeve) is screwed tightly onto the daylight optics. The counterpart, the connector, is firmly screwed onto the attachment. The design of the five locking lugs creates an absolutely bulletproof and repeatable connection between the two parts. This enables you to achieve the highest level of repeatability when aligning the attachment to the telescopic sight. The handling is nevertheless simple and easy to do even with gloves in the dark. With the DUO connector, you can alternately use the attachment on different rifle scope diameters without any modification. This enables unimagined flexibility.