Fresno Flight Center

The Banger-GT is a groove top putter has a thumb groove on the top that is designed for a better grip and a more consistent release. It is slightly overstable for hyzer or wind putts.
My Own Take on the Disc
Pro D Banger-GT
This disc is available in Pro-D @ $8, in Elite-X (Soft Banger-GT) @ $10 and Jawbreaker @ $12.
Elite X is out of stock for the moment
Jawbreaker Banger-GT