I have a Parker Magnum Crossbow, and the red dot scope that came with it was junk. However, the 3 dots are absolutely necessary, as well as knowing the distance to your target, or a deer. The factory scope was way off at 20, 40 and 50 yds. I found a Ten Point scope on e bay. The seller said he was color blind and had problems seeing the dots but it worked OK. I bought it and mounted it on my bow, and I love it. It is easy to adjust and is on at those distances. The dot contrast goes from light to heavy very easy. I would say stay with a low power scope and maybe try a green dot. There are companies around that can change the color of the dot.