This is the zen oracle putter / training aid .It’s a unique putter as it can be used as an ordinary putter while at the same time it can also be used as a training aid.. good for if you want to practice but still keep the same feel in your training aid to the actual putter that you use.It has been used by a few tour players over the years including Danny willett to name just one.The hole is just big enough for the ball to slot into and allows for a release where you would be contacting the ball

Best putter grips in the game | SuperStroke Golf