Both the Natural-Fit and the Natural-Fit LT come with Standard Grip or Super Grip coating options for the thumb piece. The Super Grip uses an advanced copolymer coating that provides a higher friction surface on the thumb piece (it is similar to a vinyl coating). This provides a grippier propulsion surface for your thumb. For those users interested in the ergonomic features of the Natural-Fit but who do not like high friction surfaces, then the standard grip may be your best choice. For users who want both the ergonomic benefits of the Natural-Fit along with a grippier propulsion surface, the Super Grip will be the better choice.