XTS Flip-up Rear Sight Black. The XTS-FRS's adjustable windage aperture makes for easy alignment and sighting in and the simplistic flip up mechanism combined with sleek styling makes this unit a terrific addition to the aesthetics and functionality of your rifle. Made from lightweight polymer plastic the XTS-FRS won't weigh your rifle down. Adding one of these to your rifle is a great idea Specifications for XTS Flip-up Rear Sight: Manufacturer: XTS Color: Black Sight Mounting Orientation: Top Mounted Sight Position: Rear Front Sight Color: REAR SIGHT ONLY Deployable: Yes Fabric/Material: Polymer Front Material: Polymer Height: 2 in Gun Type: Automatic Rifle Included Accessories: None Water Resistance Level: Yes Illumination Color: None Hand: Ambidextrous Mount Type: Picatinny Features of XTS Flip-up Rear Sight Rigged Polymer Material Adjustable Aperture (windage) Package Contents: XTS Flip-up Rear Sight XTS XTS-FRS: Flip-up Rear Sight Black