The circle on our Roundabout series of putters is the exact same size of the golf ball, 1.68 inches. The wider connection created by the arch allows for better performance on "miss hits". Each putter has a line directly above the circle. This allots the golfer the ability to line up their ball in the middle of the putter so there are no 'miss hits'. The higher MOI also produces a much smoother roll on the ball (no hop, skip, or jump).