Discraft says this about the Tracker:
Discraft Stability Rating: X-Line 1.6; Z-Line 1.8; ESP 1.8
The Tracker™ is an extra long range driver with pinpoint accuracy and superior performance. Displays flight characteristics similar to our popular Buzzz™ midrange, but longer.
This disc has been discontinued in X-Line and X-Line Fly Dy... (more)