2 & 1/16 inch High Quality ball to replace the white ball. You are buying 1 ball. Nic Barrow’s Ultimate Training Ball Improve your potting, cue ball control, and side spin skills, with world renowned snooker coach Nic Barrow’s tried and tested methods. Cue Ball – Positional Play / Cue Action This side shows you the mental map that professionals use to plan their cue ball control in any shot. Split into a green central line for beginners, and red advanced areas for side spin. Demystify positional play once and for all ! Object Ball – Aiming, Sighting & Potting This side shows a simple two step method for finding the correct contact point to pot the object ball. Training your eyes to find the correct Potting – Point on the object ball is vital for potting straight and angled shots. Give your eyes the short-cut to potting success ! Cue Ball Calculator – Break Building Place this free disc on your practice table where you want the cue ball to land. The three simple steps written on the ball FORCE YOU to plan your positional play like a professional. This dramatically increases the speed that you learn and improve your positional play and break building!