Momentus Inside Down the Line Short Track The IDL Stroke Putting Short Track is a revolutionary breakthrough in game improvement for putting. The IDL Stroke Putting Short Track will teach you to putt like the best players in the world. You will notice the ball rolling like it has over-spin on it. Inside, Down the Line is the ideal way to swing the putter if you want the ball to go down the line toward the hole. Fits perfectly in your golf bag when finished practicing for use in the future.