The Laser T is a golf training aid that provides a great way to train the correct putterface control in relation to path. The device attaches to the shaft of any putter and you align the green laser T lines so that one line is parallel to the putterface or on the top edge and the other is at right angles to the face. When you make a stroke the laser that aims toward your target should remain straight while the laser line that is on the top edge of the putter will angle open slightly on the backswing and then close slightly on the followthrough after the impact area. If the laser points to the right on the backswing the clubface is open in relation to the path, if it points to the left the clubface is closed in relation to the path. On the followthrough pointing to the right means open, pointing left means closed. The laser aiming right on the backswing and left on the throughswing will almost certainly mean over rotating of the clubface during the stroke which usually will lead to inconsistency and difficulty in squaring the clubface at impact. The same is true if the laser points left on the backswing and right on the followthrough, consistency will be difficult as will the ability to have the clubface square at impact.
When the laser remains straight throughout the stroke and in particular is straight at impact the ball with start straight and have the best possible roll.
To see a video of the Laser T and the Perfectstroke Putting Aid used together click on the following link - http://www.youtube.com/watch?v=ggoRAkS_DfA