The obj. lens is adjustable and the numbers are located on the rids of the rubber ring. The Grand Slam is one of the best scope I have and I do have a number of different ones. I had the opportunity of making a side by side comparison between my scopes set at 6 x one evening and found the clarity of the Grand Slam to be crisp and clear and at low light. This scope was equal to my Nikon Gold but not quite up to par to my Swarovskis. Before setting this scope on my Remington VLS I was using it as a spotting scope at the range and worked very well. The Grand Slam is well underrated and I’m not sure why but I’m looking at getting another one in the 3-10 x 40 mm very soon. If you have a chance take a look at one before pushing it aside because of it's name. Good luck...