D-EVO is the new scope that allows shooter to use red dot and 6X scope. Leupold gave D-EVO a nickname of 'Z scope' due to its looks. Shooter would first install a RDS like Leupold LCO(or other similar products) and then install D-EVO behind it.
From shooter's perspective, just moving eyeball a little allows user to utilize either the red dot or D-EVO's 6x magnified view.
One short-coming is the short eye relief of the D-EVO at about 4 inches. If your head is not correctly positioned, you can't see through D-EVO well and it doesn't take much for that to happen.
You can see the photo from The Firearm Blog