Designed to teach the player how to square the putter at impact, these shiny balls are joined in the middle, and will not roll straight unless perfectly struck.Customer Review: putting training aid
I bought this as a gift and have actually tried it a few times my self. It is a very challenging tool. With a lot of practice you could really improve your putting stroke. It is such a simple device however because of the simple mechanics it really allows you to repeat and correct until your swing is improved. You can tell the difference when you hit correctly.
