EVERY player should own one. Whether you're a Pro, an Instructor, a casual or serious player the 3rd Eye Stroke Trainer will be a tremendous asset to you. It's convenient, easy to use (works with or without a pool table) and is very, very effective. It attaches to the tip of your cue stick and helps you overcome initial sighting flaws, alignment flaws and Straightens Your Stroke. This product also comes with a very informative DVD in which Joe shows you why this simple tool was invented & how you can best benefit from it