Spot On Ballistic Match Technology provides precise aiming points for any Nikon BDC reticle riflescope and instant reference for sighting in other Nikon riflescopes with plex, MilDot or standard crosshair reticles. All you need is a rifle, a Nikon riflescope and a rangefinder…SpotOn does all the work for you, showing you what the possibilities are before you ever fire a shot!