The DoubleStar Flip Up Rear Sight uses A1 sight adjustment for windage and provides a bar across the top to prevent accidental adjustment of the A2 aperture. The sight is aggressively checkered on each side for no slip rapid deployment in any condition. The sight locks up but can be released by depressing the button on the side with one hande. Made of aircraft aluminum and hard coat anodized black to withstand heavy duty use.