The ShuttlePRO V.2 is designed for ergonomic integrity and maximizing productivity, allowing one-hand access to the fully programmable buttons and jog/shuttle knob. Nine (9) of the buttons have removable keycaps for easy labeling and referencing. The inner ring or 'jog' rotates through 360 degrees and provides precision frame by frame control. The outer black ring or 'shuttle' is rubberized and spring-loaded. It facilitates fast forward and rewind. You can also use the jog and shuttle for many other purposes such as scrolling, volume control, and sequencing.