100% Pure Stroke Golf Putting Aid Developed as an improvement to the original "teacher clips" the 100% Pure Stroke will detect whether or not your putting stroke is on arc, and if you have accelerated properly. The striking area is slightly enlarged which makes this product more user friendly, whereas angled planes that protrude into the striking area make the product sensitive to putts where the putter face is not square when the ball is struck. The main difference between 100% Pure Stroke and teacher clips is that 100% Pure Stroke detects off arc and decelerated putting strokes whereas teacher clips primarily detect whether or not you are striking the sweet spot. If you are looking for a user friendly, precision made practice putting device to improve arc and acceleration in your putting stroke 100% Pure Stroke is the best choice. Includes instructions, 2-way tape, plastic 'caddie' for storing when not in use and a small plastic carry case.