The KRISS Polymer Flip Rear Sight is designed to tuck completely out of vision when folded, sitting a mere 14.22mm above the rail surface. It features two apertures, 1.5mm diameter and 4.5mm diameter, for different lighting and shooting conditions. The rear sight folds down completely flat regardless of which aperture is in use, in order to be as user friendly as possible. The large integrated, textured, adjustment knob makes elevation changes with gloves simple and easy. Also available Kriss Polymer Flip Front Sight.