Welcome to Horton's Fixed non adjustable scope! I do not know which one they set that scope up for but I have yet to see one be right on for all the ranges. I had it on the super max and the thirty and forty was way off, to the point where I did not want to use them and just stayed with the 20. When I bought the Varizone from Excal fore the supermax 175 I put the multi scope on my old Supermag for my dad and it is alot closer then on my super max, but still off. If you want dead on at 20, 30, 40 and 50 then you need to get a Excal Varizone or Lumizone. They are adjustable for any CB speed.