The RT Smartknob moves focus or iris adjustment off the camera body entirely, for operators who want the control point somewhere more comfortable to reach. The included cable links it to an MK3.1 receiver or a Latitude lens controller — it controls a Canon EF or Nikon AF lens's focus and iris directly on supported RED cameras, while actuating Teradek RT lens motors requires a compatible MDR receiver such as the MK3.1, not direct control from the Smartknob alone. It also works with Latitude MDR receivers on RED cameras. A 1/4"-20 thread mounts it to a clamp or articulating arm close at hand, and the illuminated marking disk on the main knob makes lens limits easy to set and reset by feel. Six customisable buttons around the housing can be assigned to other functions, including start/stop recording, so the operator doesn't need to reach back to the camera.