NcStar Vg166 Flip Up Low Profile Black Polymer For Picatinny, Hardware Included Front And Rear Low Profile Height Sights Mount Onto 1913 Mil-Std Mil-Std Picatinny Rails. Rear Sight Has a Dual Aperture Rear Peep Sight With An Adjustable Windage Knob. Front Sight Has An Adjustable Front Sight Post With An Adjustable Elevation Knob. Flip-Up Design With Heavy Duty springs And Enhanced With Precision machined Metal Parts. Impact Resistant, Durable, Reliable, And a Lightweight Design. Made Of High Quality Polymer And Precision machined Metal. All Mounting Hardware Included. Frame Material: Polymer