M.18 medium-to-slow bubble that runs through twin markersScrews into the foresight and is held in place by a lock-collar – a C-spanner is provided to lock it in positionOnce in your position on the rifle whatever angle of cant you normally use can be set by simply rotating the whole bubble on its ratchet systemA friction collar holds your setting without need of more toolsLaser engraved degrees marked for referenceContact us at 70822-33324, if the product is in pre-order status.