No carry handle has 800m rear sights.  It's physically impossible, as the elevation screw used on fixed-handle rear sights in order to get that much elevation would extend down through the bottom of a detachable carry handle.  For this reason, ALL detachable carry handles are limited to 600m elevation adjustment, and use an elevation screw with twice the thread pitch, with .5 MOA elevation adjustment instead of 1 MOA on the fixed handles.

Don't go by the marking on the dial.  The top half of the elevation wheel, which has the numbers stamped on it, is a separate part, and some companies only buy the 800m-marked wheel and use that when assembling their carry handles.  The scale on these knobs won't match the actual settings, as the marked scale won't match the thread pitch of the bottom half of the wheel, which is what actually does the adjustments.

-Troy