The slider is reversible. Simply flip the unit over and move the camera carriage to the opposite rail to switch from straight tracking to curved parallax movement.
While it can be used on a single heavy-duty tripod via the center plate, using two tripods (one at each end) is recommended for maximum stability at the full 4ft length.
This specific model is a manual slider, providing tactile control over speed and pacing, though it can often be retrofitted with third-party motor kits.