The Dart is a small diameter putter with a straight flight. The Dart is especially good for long range putts and go-for shots. XT is a tough plastic blend that was originally developed for the Nova and Atlas. It worked so well, it spread to other models. Grip is off the charts and durability is almost as good as our premium plastics. XT is firmer than R-Pro, and less firm than KC Pro with a unique grip that feels great in the hand, and inspires confidence when throwing.