I believe he's talkin' about the Bushnel with ARC. The ARC option takes the angle of shot and compinsates the yardage for you so you know where to aim. Example is 300 yards at a 20 degree downward angle you aim as if it were at 250. They're a little more complicated than the average rangefinder, and a lot more expensive. I have the Luepold version RX-11 THAT HAS TRUE BALLISTIC RANGE. Same thing as ARC but a little cheaper. I paid about $300 for mine. I do not use the TBR option for archery, never even tried it. (I use a Predator IV pendulum sight so I don't need TBR.) IMHO even if you shoot multiple pin sights, the ARC or TBR isn't worth the extra money for archery but can be very helpful hunting big game with rifle in mountainous areas. I don't get much chance to use it deer hunting in Wisconsin but with the good 6X optics in my Luepold I can leave my small binaculars at home.