Me and My Golf Gatekeeper Putting Trainer THE GATEKEEPER The Gatekeeper: A ground-breaking product that cuts through the noise of the putting training aid market. A small & elegant device that fits easily in your bag Mini-Series Training Videos: Let Piers and Andy show you how to get the most out of the gatekeeper. With 3 training drills to improve your game. Instant Feedback: Provides instant user feedback and aids with putter path, face rotation and tempo. Difficulty Levels: Multiple ball sizes allowing you to increase the difficulty by swapping out the ball. Universal Putter Attachment: Using the universal connector, you can simply tighten the Gatekeeper onto any putter.