The Nightforce Angle Degree Indicator takes the guesswork out of uphill and downhill shots. Calibrated in degrees, it gives you an instant readout which you can enter directly into the Nightforce ballistic software or use with a pre-printed angle drop chart. Required mount (which is available for purchase separately) is designed to fit on any Mil-Std. 1913 base without removing your scope, or separately to mount on the Nightforce Ring Cap Bubble Level with Mount. For right-handed shooters; left hand Angle Degree indicator available by special order.
Big Book Catalog, Issue:68, Page:298
Sinclair, Issue:5A, Page:212