Screw-on Bubble Level Tube for 30mm sight with male x female threads to add to your existing 30mm front sight tube.
Comes with 2 changeable bubble vials for faster or dampened responses, depending on user preference.
Compatible with all 30mm sights using a 1-1/4 x 28 TPI thread.
Mounting tube has a lock ring, so it can be installed in any orientation, with the bubble on top, or below the iris, or with your preferred cant.
Bubble vials are 1/2 degree accuracy. One contains oil to dampen the bubble speed, the other mineral spirits for faster response, or on cold days