This is the Fusion 1 mile ARC that has fused ranging with magnification. This product is as set of binoculars with an extremely powerful range calculation computer in them. It has XTR technology for ultimate light transmission. The BAK-4 prisms with PC3 phase corrective coating bring superior resolution and clarity. The lens coating is rain guard HD water repellent plus the entire unit is 100 % water proof. The built in ARC (angle range compensation) is from -90 degrees to +90 degrees. There is the bow mode that provides line of sight, angle, and true horizontal distance from 10 yards. The rifle mode provides line of sight, angle, and bullet drop/holdover up to 199 inches. The VSI (variable sight in) allows sight in distance options of 100, 150, 200, or 300 yards sight in distance when in rifle mode. This range finder is packed full of technology advancements that can help make those shots that really count.