Zacuto's Flippable Reversible Z-Focus is an extremely accurate follow focus for 15mm lightweight rods. The mechanism utilizes a set of gears that connect to and spin the focus ring or Zacuto zip gear on the camera lens. The white disk allows the focus puller to create distance marks for repeatable focus pulls. This Z-Focus has a new flippable design so you can quickly remove the follow focus and flip it from the operator to the assistant side in seconds. It also has a reversible feature which allows you to quickly reverse the direction of the follow focus drive unit so it rotates in the opposite direction which is useful when focusing Nikon lenses.