The RUSAN modular adapter consists of a clamping sleeve and a connector to allow for repeatable and precise mounting of the front attachment. The connector is screwed onto the front attachment and remains there permanently - even when disassembled. This ensures that the point of impact remains exactly the same after mounting or dismounting the front attachment. The connector is quickly connected to the clamping sleeve, which is clamped onto the daylight optic, via a bayonet closure.