The Cannon is mounted under the rod in line with the rings and as near to directly over the spool. Unfortunately there is a wide variety of reels and reel fittings and many vary as to how they are fitted. Attach the Cannon onto the rod with insulating tape until you are happy with its position.
Always check that your clutch is tight before casting in areas where big fish are regularly caught winding your leader around the Cannon three times will allow you to cast with a light clutch fitting.