You where almost there, go to your posted hyper-link, on the left hand completely there's an I(capital i symbol), click on it. Within this upper new menu you'll get an Accrobat file(use the Accrobat to print, and not the browser's print file). These files are long to download but if downloaded directly to your computer they'll be much faster. Have a serious look at their Red dot aiming device for the 527, 550.