The N85 Macro Port 120 is designed to work with the OM Systems M.Zuiko ED 90mm F3.5 Macro IS PRO lens and is capable of operating the lens' focus distance switch underwater. This switch allows for setting the focus distance and, thereby, the maximum magnification of the lens with three options: 'super macro', '0.25 - 0.5m', and '0.5m to infinity'. A window on the port allows for easily visually confirming the switch's location.