What is the PutterBuddy?  

It's a removable alignment aid made specifically for the heel shafted Odyssey 2 Ball putter.  

Odyssey made a "pro" version of this model, arguably one of the 3 most popular putters ever made, which had a thin line to aid in alignment.  A lot of people added that line themselves because it's a great way to extend the alignment line on your golfball.  However, if you're like me, the chances that the line is dead straight...or exactly in the middle of the circles were pretty slim!  So that's where PutterBuddy comes in!  Its easy to put on your putter and almost impossible to misalign it because of it's design.