Nikon Prostaff 1000 Laser Rangefinder, 1000 Yards, Black - 16664 Nikon’s advanced ID Incline/Decline Technology provides the horizontal distance to the target, even when ranging at various incline or decline shooting angles up to an incredible +/- 89 degrees nearly vertical up or down. PROSTAFF 1000 allows user to switch between horizontal distance or actual distance modes.