The RTS sight is a set of a front and rear sight which are both set to the 45 degree position, which can be at either the left or right side for ambidextrous users. These sights are used when an optic blocks the vision of any back up sight, like a sniper scope. At the 45 degree position the operator simply has to tilt his airsoft gun for his eyes to align with the RTS sights. There is no longer a need to remove the mounted optic.
The RTS sights fit onto 20mm rails.