From CallawayGolf.com: " Odyssey's new line of Ai-ONE Square 2 Square putters feature a modern center shafted design that makes them Stroke Balanced so they want to stay square throughout a golfer's stroke. These putters are ideally suited for golfer’s looking to minimize their face rotation when they putt."
   
 
   Square 2 Square Oversize Grip = No Upcharge - More Rounded, Traditional Style Grip, Slightly oversized similar to a Superstroke 2.0 thickness 
   
 
   Square 2 Square Reverse Taper Grip = $30+ Online Upcharge 
   
 
   From CallawayGolf.Com: "    Introducing our new Reverse Taper Grip—engineered specifically for Square 2 Square models to promote a more natural setup position. This custom option is designed to counteract the 2° of shaft lean that these Square 2 Square putters have and get the leading edge of the grip perpendicular to the ground. An upcharge applies."