Upgrade your Lab Golf Directed Force DF3 putter with a custom white, black or orange "Odyssey 2 Ball" insert.  Each insert is custom made and 3D printed to fit perfectly in the empty hole giving you a solid and easy to align visual putting aid.  A large empty hole can be distracting to some and the Odyssey 2 Ball alignment system has been time proven as a wonderful way to line up your putt. Line up the insert with the small tab facing the back of the putter as represented in the picture.  Will stay in place and will not rattle or vibrate.