Inseyed putters have a patented alignment system that guarentees a golfer has their eyes directly over the ball everytime which is the optimum position. These putters have been rated for pure roll, as some of the best ever tested by Swing Dynamics of Carlsbad, CA. Coupled with the patented alignment system they are probably the most accurate putters made. A golfer should be able to knock 1 - 5 putts off their game using these putters.