Discraft says this about the Putt'r:
Discraft Stability Rating: X-Line 0.0; Z-Line 0.0
The Putt'r™ is an excellent turnover approach putter. It goes super straight, and feels great in your hand. The Putt'r™ has been referred to by some as the best putter ever!
This disc has been discontinued in Z-Line and Z-Line Fly Dye.... (more)