The Swarovski scopenis correct and the mount was designed for the rifleDonut reticle in the Swarovski opticFolding rear sightNote how the iron sight folds down into a recess in the top rail.Folding front sight that inspired the future LE6940/LE901 folding front sight.Hydraulic bufferThe M16A2E1 uses the ACR collapsible stock
The Colt AR-15 Resource 