Dear，Pls leave a massage to tell us what design (Color) do you want.thank you.

Description:The MBUS back-up sight is a low-cost， folding back-up sight. The dual aperture MBUS Rear Sight is adjustable for windage and fits all 20mm rail equipped weapons， but is specifically tailored to the M4/M16 AEG series.Main Feature:Spring-loaded flip up sightEasily activated from either side or by pressing the topFor M4/M16 AEG with standard 20mm RailDurable DuPont Polymer constructionSpecification:Weight: 0.09 kgSize: 6.5 x 3 x 1.8 cmPackage Content:2 x MBUS Back-up Sight