An flip up sight, styled on the looks of the Magpul MBUS flip-up. Few things still to be developed (height adjustment, rear sight analog part, torsion spring), but should work just fine. As soon as i get the part from e-prototypy, i'll post some pics.You'll need:Assembly is quite simple. Attach the release to the bottom piece with the 2.5mm steel rod, put the large spring under it, press it down and attach the sight with the second rod. Last, place the rubber band into the notches on the side and bottom piece. To mount the sight on the rail, slide it on, put in place, insert the nut into the right side socket, then put the screw into the other-side hole, and screw in tightly.