This Smart Iris Marking Ring from ARRI is an auto-detectable iris ring that is plug-and-play when used with the optional Hi-5 hand unit. It features a preprinted precision iris scale with markings from T1.0 to T22, allowing you to accurately adjust the iris from the handwheel. Mounting the iris scale to your Hi-5 shifts the iris scale to the knob side of the lens data display. This provides the operator/DIT with control of the iris motor utilizing the full rotation range of the control knob.