From the Manufacturer...
The SL is a fast, dependable disc with a long straight flight and excellent glide. This disc can add measurable distance to your drives. With its quickness, slight high speed turn, long glide and low fade, the SL will fly a long way. The Pro version is called the Pro Starfire.
Weight Range: Star:165-175g, Pro:165-175g
Best Choice for: Distance drives with accuracy, Tailwind drives, Low canopy, straight drives
Available Plastics: Star, Pro